> 在pycharm中完美运行的代码在部署到服务器后为什么会出现ModuleNotFoundError：no model named *呢？ #### 原因 因为工作路径的问题。当你在pycharm运行程序的时候，pycharm默认将你当前的文件夹作为了工作路径，那么你 import 你的模块也就顺理成章了，但是在终端就不一样了哦。原因是…（PYTHONPATH, 等） #### 解决 ##### 方法一 在你的主程序，也就是你想要在终端运行但是报错的程序中加入工作路径就好了： ``` import os import sys sys.path.append(os.path.dirname(os.path.abspath(__file__)) + '/../../') # 就是将你上层的文件夹添加到工作路径，当然包括文件夹下。 # 注意这三行要放到你要导入的模块的前面 ``` ##### 方法二 配置环境变量PYTHONPATH 默认我们import的模块都会从PYTHONPATH里面寻找。

<p style="white-space: normal;letter-spacing: 0.544px;background-color: rgb(255, 255, 255);text-align: center;" data-mpa-powered-by="yiban.io"><span style="letter-spacing: 0.544px;widows: 1;word-spacing: 2px;caret-color: rgb(51, 51, 51);font-family: Optima-Regular, PingFangTC-light;color: rgb(127, 127, 127);font-size: 14px;line-height: 1.75em;"></span></p> <p style="margin-bottom: 10px;font-family: -apple-system-font, BlinkMacSystemFont, &quot;Helvetica Neue&quot;, &quot;PingFang SC&quot;, &quot;Hiragino Sans GB&quot;, &quot;Microsoft YaHei UI&quot;, &quot;Microsoft YaHei&quot;, Arial, sans-serif;letter-spacing: 0.544px;white-space: normal;color: rgb(62, 62, 62);font-size: 15px;background-color: rgb(255, 255, 255);line-height: normal;text-align: center;"><span style="font-size: 14px;letter-spacing: 0.544px;word-spacing: 2px;color: rgb(136, 136, 136);">点击蓝色“</span><span style="font-size: 14px;letter-spacing: 0.544px;word-spacing: 2px;color: rgb(0, 128, 255);">架构文摘</span><span style="font-size: 14px;letter-spacing: 0.544px;word-spacing: 2px;color: rgb(136, 136, 136);">”关注我哟</span></p> <p style="margin-bottom: 10px;font-family: -apple-system-font, BlinkMacSystemFont, &quot;Helvetica Neue&quot;, &quot;PingFang SC&quot;, &quot;Hiragino Sans GB&quot;, &quot;Microsoft YaHei UI&quot;, &quot;Microsoft YaHei&quot;, Arial, sans-serif;letter-spacing: 0.544px;white-space: normal;color: rgb(62, 62, 62);font-size: 15px;background-color: rgb(255, 255, 255);text-size-adjust: auto;word-spacing: 2px;text-align: center;"><span style="font-size: 14px;color: rgb(136, 136, 136);">加个“</span><span style="color: rgb(0, 128, 255);font-size: 14px;">星标</span><span style="font-size: 14px;color: rgb(136, 136, 136);">”，每天上午 09:25，干货推送！</span></p> <p style="font-family: -apple-system-font, system-ui, &quot;Helvetica Neue&quot;, &quot;PingFang SC&quot;, &quot;Hiragino Sans GB&quot;, &quot;Microsoft YaHei UI&quot;, &quot;Microsoft YaHei&quot;, Arial, sans-serif;letter-spacing: 0.544px;white-space: normal;color: rgb(62, 62, 62);font-size: 14px;background-color: rgb(255, 255, 255);text-align: center;"><img data-backh="36" data-backw="578" data-ratio="0.0625" data-s="300,640" data-type="jpeg" data-w="640" width="100%" src="/upload/8c292e55ba5a23cb6ebc11f2a2c4fece.jpg" style="font-family: -apple-system-font, BlinkMacSystemFont, &quot;Helvetica Neue&quot;, &quot;PingFang SC&quot;, &quot;Hiragino Sans GB&quot;, &quot;Microsoft YaHei UI&quot;, &quot;Microsoft YaHei&quot;, Arial, sans-serif;letter-spacing: 0.544px;widows: 1;word-spacing: 2px;color: rgb(136, 136, 136);box-sizing: border-box !important;visibility: visible !important;width: 677px !important;"></p> <section> <p><span style="font-size: 12px;color: rgb(136, 136, 136);"><em><span style="font-size: 12px;text-align: right;">作者：Jedrzejewski</span></em></span></p> <p><span style="font-size: 12px;color: rgb(136, 136, 136);"><em><span style="color: rgb(136, 136, 136);font-size: 12px;text-align: right;">来源：e4developer.com/2018/08/06/</span></em></span></p> </section> <p><br></p> <hr style="border-style: solid;border-width: 1px 0px 0px;border-color: rgba(0, 0, 0, 0.1);transform-origin: 0px 0px;transform: scale(1, 0.5);"> <p><span style="font-size: 15px;color: rgb(80, 97, 109);font-family: Helvetica, Arial, sans-serif;text-align: start;">Spring Boot 是最流行的用于开发微服务的 Java 框架。在本文中，我将与你分享自 2016 年以来我在专业开发中使用 Spring Boot 所采用的最佳实践。这些内容是基于我的个人经验和一些熟知的 Spring Boot 专家的文章。<br></span></p> <p style="box-sizing: border-box;margin-top: 15px;margin-bottom: 15px;color: rgb(80, 97, 109);font-family: Helvetica, Arial, sans-serif;font-size: 15px;text-align: start;white-space: normal;"><span style="font-size: 15px;">在本文中，我将重点介绍 Spring Boot 特有的实践（大多数时候，也适用于 Spring 项目）。以下依次列出了最佳实践，排名不分先后。</span></p> <h3 style="box-sizing: border-box;margin-top: 2rem;margin-bottom: 0.5rem;font-weight: 700;color: rgb(255, 140, 0);line-height: 1.35;font-size: 18px;text-align: start;white-space: normal;font-family: Menlo, Monaco, 'Source Code Pro', Consolas, Inconsolata, 'Ubuntu Mono', 'DejaVu Sans Mono', 'Courier New', 'Droid Sans Mono', 'Hiragino Sans GB', 微软雅黑, monospace !important;"><span style="font-size: 15px;color: rgb(123, 12, 0);">1、使用自定义 BOM 来维护第三方依赖</span></h3> <p style="box-sizing: border-box;margin-top: 15px;margin-bottom: 15px;color: rgb(80, 97, 109);font-family: Helvetica, Arial, sans-serif;font-size: 15px;text-align: start;white-space: normal;"><span style="font-size: 15px;">这条实践是我根据实际项目中的经历总结出的。</span></p> <p style="box-sizing: border-box;margin-top: 15px;margin-bottom: 15px;color: rgb(80, 97, 109);font-family: Helvetica, Arial, sans-serif;font-size: 15px;text-align: start;white-space: normal;"><span style="font-size: 15px;">Spring Boot 项目本身使用和集成了大量的开源项目，它帮助我们维护了这些第三方依赖。但是也有一部分在实际项目使用中并没有包括进来，这就需要我们在项目中自己维护版本。如果在一个大型的项目中，包括了很多未开发模块，那么维护起来就非常的繁琐。</span></p> <p style="box-sizing: border-box;margin-top: 15px;margin-bottom: 15px;color: rgb(80, 97, 109);font-family: Helvetica, Arial, sans-serif;font-size: 15px;text-align: start;white-space: normal;"><span style="font-size: 15px;">怎么办呢？事实上，Spring IO Platform 就是做的这个事情，它本身就是 Spring Boot 的子项目，同时维护了其他第三方开源库。我们可以借鉴 Spring IO Platform 来编写自己的基础项目 platform-bom，所有的业务模块项目应该以 BOM 的方式引入。这样在升级第三方依赖时，就只需要升级这一个依赖的版本而已。</span></p> <pre style="box-sizing: border-box;padding: 0.5em;font-family: Courier, 'Courier New', monospace;background: rgb(45, 45, 45);border-width: 1px;border-style: solid;border-color: rgb(221, 221, 221);overflow-x: auto;color: rgb(204, 204, 204);font-size: 15px;text-align: start;"><code style=""><span style="font-size: 15px;">&lt;dependencyManagement&gt;<br>&nbsp;&nbsp;&nbsp;&lt;dependencies&gt;<br>&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&lt;dependency&gt;<br>&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&lt;groupId&gt;io.spring.platform&lt;/groupId&gt;<br>&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&lt;artifactId&gt;platform-bom&lt;/artifactId&gt;<br>&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&lt;version&gt;Cairo-SR3&lt;/version&gt;<br>&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&lt;type&gt;pom&lt;/type&gt;<br>&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&lt;scope&gt;<span style="box-sizing: border-box;font-weight: 700;color: rgb(204, 153, 204);">import</span>&lt;/scope&gt;<br>&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&lt;/dependency&gt;<br>&nbsp;&nbsp;&nbsp;&lt;/dependencies&gt;<br>&lt;/dependencyManagement&gt;<br></span></code></pre> <h3 style="box-sizing: border-box;margin-top: 2rem;margin-bottom: 0.5rem;font-weight: 700;color: rgb(255, 140, 0);line-height: 1.35;font-size: 18px;text-align: start;white-space: normal;font-family: Menlo, Monaco, 'Source Code Pro', Consolas, Inconsolata, 'Ubuntu Mono', 'DejaVu Sans Mono', 'Courier New', 'Droid Sans Mono', 'Hiragino Sans GB', 微软雅黑, monospace !important;"><span style="font-size: 15px;color: rgb(123, 12, 0);">2、使用自动配置</span></h3> <p style="box-sizing: border-box;margin-top: 15px;margin-bottom: 15px;color: rgb(80, 97, 109);font-family: Helvetica, Arial, sans-serif;font-size: 15px;text-align: start;white-space: normal;"><span style="font-size: 15px;">Spring Boot 的一个主要特性是使用自动配置。这是 Spring Boot 的一部分，它可以简化你的代码并使之工作。当在类路径上检测到特定的 jar 文件时，自动配置就会被激活。</span></p> <p style="box-sizing: border-box;margin-top: 15px;margin-bottom: 15px;color: rgb(80, 97, 109);font-family: Helvetica, Arial, sans-serif;font-size: 15px;text-align: start;white-space: normal;"><span style="font-size: 15px;">使用它的最简单方法是依赖 Spring Boot Starters。因此，如果你想与 Redis 进行集成，你可以首先包括：</span></p> <pre style="box-sizing: border-box;padding: 0.5em;font-family: Courier, 'Courier New', monospace;background: rgb(45, 45, 45);border-width: 1px;border-style: solid;border-color: rgb(221, 221, 221);overflow-x: auto;color: rgb(204, 204, 204);font-size: 15px;text-align: start;"><code style=""><span style="font-size: 15px;">&lt;dependency&gt;<br>&nbsp;&nbsp;&nbsp;&lt;groupId&gt;org.springframework.boot&lt;/groupId&gt;<br>&nbsp;&nbsp;&nbsp;&lt;artifactId&gt;spring-boot-starter-data-redis&lt;/artifactId&gt;<br>&lt;/dependency&gt;<br></span></code></pre> <p style="box-sizing: border-box;margin-top: 15px;margin-bottom: 15px;color: rgb(80, 97, 109);font-family: Helvetica, Arial, sans-serif;font-size: 15px;text-align: start;white-space: normal;"><span style="font-size: 15px;">如果你想与 MongoDB 进行集成，需要这样：</span></p> <pre style="box-sizing: border-box;padding: 0.5em;font-family: Courier, 'Courier New', monospace;background: rgb(45, 45, 45);border-width: 1px;border-style: solid;border-color: rgb(221, 221, 221);overflow-x: auto;color: rgb(204, 204, 204);font-size: 15px;text-align: start;"><code style=""><span style="font-size: 15px;">&lt;dependency&gt;<br>&nbsp;&nbsp;&nbsp;&lt;groupId&gt;org.springframework.boot&lt;/groupId&gt;<br>&nbsp;&nbsp;&nbsp;&lt;artifactId&gt;spring-boot-starter-data-mongodb&lt;/artifactId&gt;<br>&lt;/dependency&gt;<br></span></code></pre> <p style="box-sizing: border-box;margin-top: 15px;margin-bottom: 15px;color: rgb(80, 97, 109);font-family: Helvetica, Arial, sans-serif;font-size: 15px;text-align: start;white-space: normal;"><span style="font-size: 15px;">借助于这些 starters，这些繁琐的配置就可以很好地集成起来并协同工作，而且它们都是经过测试和验证的。这非常有助于避免可怕的 Jar 地狱。</span></p> <blockquote style="box-sizing: border-box;margin-bottom: 1.2em;padding: 15px 15px 15px 1rem;color: rgb(129, 145, 152);border-left-width: 6px;border-left-color: rgb(96, 125, 139);font-size: 14px;line-height: 18px;background: rgb(242, 247, 251);font-family: Helvetica, Arial, sans-serif;text-align: start;white-space: normal;"> <p style="box-sizing: border-box;"><span style="font-size: 15px;">https://dzone.com/articles/what-is-jar-hell</span></p> </blockquote> <p style="box-sizing: border-box;margin-top: 15px;margin-bottom: 15px;color: rgb(80, 97, 109);font-family: Helvetica, Arial, sans-serif;font-size: 15px;text-align: start;white-space: normal;"><span style="font-size: 15px;">通过使用以下注解属性，可以从自动配置中排除某些配置类：</span></p> <pre style="box-sizing: border-box;padding: 0.5em;font-family: Courier, 'Courier New', monospace;background: rgb(45, 45, 45);border-width: 1px;border-style: solid;border-color: rgb(221, 221, 221);overflow-x: auto;color: rgb(204, 204, 204);font-size: 15px;text-align: start;"><code style=""><span style="font-size: 15px;"><span style="box-sizing: border-box;color: rgb(249, 145, 87);">@EnableAutoConfiguration</span>（exclude&nbsp;=&nbsp;{ClassNotToAutoconfigure.class}）<br></span></code></pre> <p style="box-sizing: border-box;margin-top: 15px;margin-bottom: 15px;color: rgb(80, 97, 109);font-family: Helvetica, Arial, sans-serif;font-size: 15px;text-align: start;white-space: normal;"><span style="font-size: 15px;">但只有在绝对必要时才应该这样做。</span></p> <p style="box-sizing: border-box;margin-top: 15px;margin-bottom: 15px;color: rgb(80, 97, 109);font-family: Helvetica, Arial, sans-serif;font-size: 15px;text-align: start;white-space: normal;"><span style="font-size: 15px;">有关自动配置的官方文档可在此处找到：</span></p> <blockquote style="box-sizing: border-box;margin-bottom: 1.2em;padding: 15px 15px 15px 1rem;color: rgb(129, 145, 152);border-left-width: 6px;border-left-color: rgb(96, 125, 139);font-size: 14px;line-height: 18px;background: rgb(242, 247, 251);font-family: Helvetica, Arial, sans-serif;text-align: start;white-space: normal;"> <p style="box-sizing: border-box;"><span style="font-size: 15px;">https://docs.spring.io/spring-boot/docs/current/reference/html/using-boot-auto-configuration.html。</span></p> </blockquote> <h3 style="box-sizing: border-box;margin-top: 2rem;margin-bottom: 0.5rem;font-weight: 700;color: rgb(255, 140, 0);line-height: 1.35;font-size: 18px;text-align: start;white-space: normal;font-family: Menlo, Monaco, 'Source Code Pro', Consolas, Inconsolata, 'Ubuntu Mono', 'DejaVu Sans Mono', 'Courier New', 'Droid Sans Mono', 'Hiragino Sans GB', 微软雅黑, monospace !important;"><span style="font-size: 15px;color: rgb(123, 12, 0);">3、使用 Spring Initializr 来开始一个新的 Spring Boot 项目</span></h3> <blockquote style="box-sizing: border-box;margin-bottom: 1.2em;padding: 15px 15px 15px 1rem;color: rgb(129, 145, 152);border-left-width: 6px;border-left-color: rgb(96, 125, 139);font-size: 14px;line-height: 18px;background: rgb(242, 247, 251);font-family: Helvetica, Arial, sans-serif;text-align: start;white-space: normal;"> <p style="box-sizing: border-box;"><span style="font-size: 15px;">这一条最佳实践来自 Josh Long （Spring Advocate，@starbuxman）。</span></p> </blockquote> <p style="box-sizing: border-box;margin-top: 15px;margin-bottom: 15px;color: rgb(80, 97, 109);font-family: Helvetica, Arial, sans-serif;font-size: 15px;text-align: start;white-space: normal;"><span style="font-size: 15px;">Spring Initializr 提供了一个超级简单的方法来创建一个新的 Spring Boot 项目，并根据你的需要来加载可能使用到的依赖。</span></p> <blockquote style="box-sizing: border-box;margin-bottom: 1.2em;padding: 15px 15px 15px 1rem;color: rgb(129, 145, 152);border-left-width: 6px;border-left-color: rgb(96, 125, 139);font-size: 14px;line-height: 18px;background: rgb(242, 247, 251);font-family: Helvetica, Arial, sans-serif;text-align: start;white-space: normal;"> <p style="box-sizing: border-box;"><span style="font-size: 15px;">https://start.spring.io/</span></p> </blockquote> <p style="box-sizing: border-box;margin-top: 15px;margin-bottom: 15px;color: rgb(80, 97, 109);font-family: Helvetica, Arial, sans-serif;font-size: 15px;text-align: start;white-space: normal;"><span style="font-size: 15px;">使用 Initializr 创建应用程序可确保你获得经过测试和验证的依赖项，这些依赖项适用于 Spring 自动配置。你甚至可能会发现一些新的集成，但你可能并没有意识到这些。</span></p> <h3 style="box-sizing: border-box;margin-top: 2rem;margin-bottom: 0.5rem;font-weight: 700;color: rgb(255, 140, 0);line-height: 1.35;font-size: 18px;text-align: start;white-space: normal;font-family: Menlo, Monaco, 'Source Code Pro', Consolas, Inconsolata, 'Ubuntu Mono', 'DejaVu Sans Mono', 'Courier New', 'Droid Sans Mono', 'Hiragino Sans GB', 微软雅黑, monospace !important;"><span style="font-size: 15px;color: rgb(123, 12, 0);">4、考虑为常见的组织问题创建自己的自动配置</span></h3> <p style="box-sizing: border-box;margin-top: 15px;margin-bottom: 15px;color: rgb(80, 97, 109);font-family: Helvetica, Arial, sans-serif;font-size: 15px;text-align: start;white-space: normal;"><span style="font-size: 15px;">这一条也来自 Josh Long（Spring Advocate，@starbuxman）——这个实践是针对高级用户的。</span></p> <p style="box-sizing: border-box;margin-top: 15px;margin-bottom: 15px;color: rgb(80, 97, 109);font-family: Helvetica, Arial, sans-serif;font-size: 15px;text-align: start;white-space: normal;"><span style="font-size: 15px;">如果你在一个严重依赖 Spring Boot 的公司或团队中工作，并且有共同的问题需要解决，那么你可以创建自己的自动配置。</span></p> <p style="box-sizing: border-box;margin-top: 15px;margin-bottom: 15px;color: rgb(80, 97, 109);font-family: Helvetica, Arial, sans-serif;font-size: 15px;text-align: start;white-space: normal;"><span style="font-size: 15px;">这项任务涉及较多工作，因此你需要考虑何时获益是值得投入的。与多个略有不同的定制配置相比，维护单个自动配置更容易。</span></p> <p style="box-sizing: border-box;margin-top: 15px;margin-bottom: 15px;color: rgb(80, 97, 109);font-family: Helvetica, Arial, sans-serif;font-size: 15px;text-align: start;white-space: normal;"><span style="font-size: 15px;">如果将这个提供 Spring Boot 配置以开源库的形式发布出去，那么将极大地简化数千个用户的配置工作。</span></p> <h3 style="box-sizing: border-box;margin-top: 2rem;margin-bottom: 0.5rem;font-weight: 700;color: rgb(255, 140, 0);line-height: 1.35;font-size: 18px;text-align: start;white-space: normal;font-family: Menlo, Monaco, 'Source Code Pro', Consolas, Inconsolata, 'Ubuntu Mono', 'DejaVu Sans Mono', 'Courier New', 'Droid Sans Mono', 'Hiragino Sans GB', 微软雅黑, monospace !important;"><span style="font-size: 15px;color: rgb(123, 12, 0);">5、正确设计代码目录结构</span></h3> <p style="box-sizing: border-box;margin-top: 15px;margin-bottom: 15px;color: rgb(80, 97, 109);font-family: Helvetica, Arial, sans-serif;font-size: 15px;text-align: start;white-space: normal;"><span style="font-size: 15px;">尽管允许你有很大的自由，但是有一些基本规则值得遵守来设计你的源代码结构。</span></p> <p style="box-sizing: border-box;margin-top: 15px;margin-bottom: 15px;color: rgb(80, 97, 109);font-family: Helvetica, Arial, sans-serif;font-size: 15px;text-align: start;white-space: normal;"><span style="font-size: 15px;">避免使用默认包。确保所有内容（包括你的入口点）都位于一个名称很好的包中，这样就可以避免与装配和组件扫描相关的意外情况；</span></p> <p style="box-sizing: border-box;margin-top: 15px;margin-bottom: 15px;color: rgb(80, 97, 109);font-family: Helvetica, Arial, sans-serif;font-size: 15px;text-align: start;white-space: normal;"><span style="font-size: 15px;">将 Application.java（应用的入口类）保留在顶级源代码目录中；</span></p> <p style="box-sizing: border-box;margin-top: 15px;margin-bottom: 15px;color: rgb(80, 97, 109);font-family: Helvetica, Arial, sans-serif;font-size: 15px;text-align: start;white-space: normal;"><span style="font-size: 15px;">我建议将控制器和服务放在以功能为导向的模块中，但这是可选的。一些非常好的开发人员建议将所有控制器放在一起。不论怎样，坚持一种风格！</span></p> <h3 style="box-sizing: border-box;margin-top: 2rem;margin-bottom: 0.5rem;font-weight: 700;color: rgb(255, 140, 0);line-height: 1.35;font-size: 18px;text-align: start;white-space: normal;font-family: Menlo, Monaco, 'Source Code Pro', Consolas, Inconsolata, 'Ubuntu Mono', 'DejaVu Sans Mono', 'Courier New', 'Droid Sans Mono', 'Hiragino Sans GB', 微软雅黑, monospace !important;"><span style="font-size: 15px;color: rgb(123, 12, 0);">6、保持 @Controller 的简洁和专注</span></h3> <p style="box-sizing: border-box;margin-top: 15px;margin-bottom: 15px;color: rgb(80, 97, 109);font-family: Helvetica, Arial, sans-serif;font-size: 15px;text-align: start;white-space: normal;"><span style="font-size: 15px;">Controller 应该非常简单。你可以在此处阅读有关 GRASP 中有关控制器模式部分的说明。你希望控制器作为协调和委派的角色，而不是执行实际的业务逻辑。以下是主要做法：</span></p> <blockquote style="box-sizing: border-box;margin-bottom: 1.2em;padding: 15px 15px 15px 1rem;color: rgb(129, 145, 152);border-left-width: 6px;border-left-color: rgb(96, 125, 139);font-size: 14px;line-height: 18px;background: rgb(242, 247, 251);font-family: Helvetica, Arial, sans-serif;text-align: start;white-space: normal;"> <p style="box-sizing: border-box;"><span style="font-size: 15px;">https://en.wikipedia.org/wiki/GRASP_(object-oriented_design)#Controller</span></p> </blockquote> <ul style="padding-left: 20px;list-style: square;color: rgb(80, 97, 109);font-family: Helvetica, Arial, sans-serif;font-size: 15px;text-align: start;white-space: normal;margin-top: 2px !important;" class="list-paddingleft-2"> <li style="box-sizing: border-box;margin-top: 2px !important;font-size: 15px;"><p style="box-sizing: border-box;margin-bottom: 15px;"><span style="font-size: 15px;">控制器应该是无状态的！默认情况下，控制器是单例，并且任何状态都可能导致大量问题；</span></p></li> <li style="box-sizing: border-box;margin-top: 2px !important;font-size: 15px;"><p style="box-sizing: border-box;margin-bottom: 15px;"><span style="font-size: 15px;">控制器不应该执行业务逻辑，而是依赖委托；</span></p></li> <li style="box-sizing: border-box;margin-top: 2px !important;font-size: 15px;"><p style="box-sizing: border-box;margin-bottom: 15px;"><span style="font-size: 15px;">控制器应该处理应用程序的 HTTP 层，这不应该传递给服务；</span></p></li> <li style="box-sizing: border-box;margin-top: 2px !important;font-size: 15px;"><p style="box-sizing: border-box;margin-bottom: 15px;"><span style="font-size: 15px;">控制器应该围绕用例 / 业务能力来设计。</span></p></li> </ul> <p style="box-sizing: border-box;margin-top: 15px;margin-bottom: 15px;color: rgb(80, 97, 109);font-family: Helvetica, Arial, sans-serif;font-size: 15px;text-align: start;white-space: normal;"><span style="font-size: 15px;">要深入这个内容，需要进一步地了解设计 REST API 的最佳实践。无论你是否想要使用 Spring Boot，都是值得学习的。</span></p> <h3 style="box-sizing: border-box;margin-top: 2rem;margin-bottom: 0.5rem;font-weight: 700;color: rgb(255, 140, 0);line-height: 1.35;font-size: 18px;text-align: start;white-space: normal;font-family: Menlo, Monaco, 'Source Code Pro', Consolas, Inconsolata, 'Ubuntu Mono', 'DejaVu Sans Mono', 'Courier New', 'Droid Sans Mono', 'Hiragino Sans GB', 微软雅黑, monospace !important;"><span style="font-size: 15px;color: rgb(123, 12, 0);">7、围绕业务功能构建 @Service</span></h3> <p style="box-sizing: border-box;margin-top: 15px;margin-bottom: 15px;color: rgb(80, 97, 109);font-family: Helvetica, Arial, sans-serif;font-size: 15px;text-align: start;white-space: normal;"><span style="font-size: 15px;">Service 是 Spring Boot 的另一个核心概念。我发现最好围绕业务功能 / 领域 / 用例（无论你怎么称呼都行）来构建服务。</span></p> <p style="box-sizing: border-box;margin-top: 15px;margin-bottom: 15px;color: rgb(80, 97, 109);font-family: Helvetica, Arial, sans-serif;font-size: 15px;text-align: start;white-space: normal;"><span style="font-size: 15px;">在应用中设计名称类似</span><code style=""><span style="font-size: 15px;">AccountService</span></code><span style="font-size: 15px;">,&nbsp;</span><code style=""><span style="font-size: 15px;">UserService</span></code><span style="font-size: 15px;">,&nbsp;</span><code style=""><span style="font-size: 15px;">PaymentService</span></code><span style="font-size: 15px;">这样的服务，比起像</span><code style=""><span style="font-size: 15px;">DatabaseService</span></code><span style="font-size: 15px;">、</span><code style=""><span style="font-size: 15px;">ValidationService</span></code><span style="font-size: 15px;">、</span><code style=""><span style="font-size: 15px;">CalculationService</span></code><span style="font-size: 15px;">这样的会更合适一些。</span></p> <p style="box-sizing: border-box;margin-top: 15px;margin-bottom: 15px;color: rgb(80, 97, 109);font-family: Helvetica, Arial, sans-serif;font-size: 15px;text-align: start;white-space: normal;"><span style="font-size: 15px;">你可以决定使用 Controler 和 Service 之间的一对一映射，那将是理想的情况。但这并不意味着，Service 之间不能互相调用！</span></p> <h3 style="box-sizing: border-box;margin-top: 2rem;margin-bottom: 0.5rem;font-weight: 700;color: rgb(255, 140, 0);line-height: 1.35;font-size: 18px;text-align: start;white-space: normal;font-family: Menlo, Monaco, 'Source Code Pro', Consolas, Inconsolata, 'Ubuntu Mono', 'DejaVu Sans Mono', 'Courier New', 'Droid Sans Mono', 'Hiragino Sans GB', 微软雅黑, monospace !important;"><span style="font-size: 15px;color: rgb(123, 12, 0);">8、使数据库独立于核心业务逻辑之外</span></h3> <p style="box-sizing: border-box;margin-top: 15px;margin-bottom: 15px;color: rgb(80, 97, 109);font-family: Helvetica, Arial, sans-serif;font-size: 15px;text-align: start;white-space: normal;"><span style="font-size: 15px;">我之前还不确定如何在 Spring Boot 中最好地处理数据库交互。在阅读了罗伯特 ·C· 马丁的 “Clear Architecture” 之后，对我来说就清晰多了。</span></p> <p style="box-sizing: border-box;margin-top: 15px;margin-bottom: 15px;color: rgb(80, 97, 109);font-family: Helvetica, Arial, sans-serif;font-size: 15px;text-align: start;white-space: normal;"><span style="font-size: 15px;">你希望你的数据库逻辑于服务分离出来。理想情况下，你不希望服务知道它正在与哪个数据库通信，这需要一些抽象来封装对象的持久性。</span></p> <blockquote style="box-sizing: border-box;margin-bottom: 1.2em;padding: 15px 15px 15px 1rem;color: rgb(129, 145, 152);border-left-width: 6px;border-left-color: rgb(96, 125, 139);font-size: 14px;line-height: 18px;background: rgb(242, 247, 251);font-family: Helvetica, Arial, sans-serif;text-align: start;white-space: normal;"> <p style="box-sizing: border-box;"><span style="font-size: 15px;">罗伯特 C. 马丁强烈地说明，你的数据库是一个 “细节”，这意味着不将你的应用程序与特定数据库耦合。过去很少有人会切换数据库，我注意到，使用 Spring Boot 和现代微服务开发会让事情变得更快。</span></p> </blockquote> <h3 style="box-sizing: border-box;margin-top: 2rem;margin-bottom: 0.5rem;font-weight: 700;color: rgb(255, 140, 0);line-height: 1.35;font-size: 18px;text-align: start;white-space: normal;font-family: Menlo, Monaco, 'Source Code Pro', Consolas, Inconsolata, 'Ubuntu Mono', 'DejaVu Sans Mono', 'Courier New', 'Droid Sans Mono', 'Hiragino Sans GB', 微软雅黑, monospace !important;"><span style="font-size: 15px;color: rgb(123, 12, 0);">9、保持业务逻辑不受 Spring Boot 代码的影响</span></h3> <p style="box-sizing: border-box;margin-top: 15px;margin-bottom: 15px;color: rgb(80, 97, 109);font-family: Helvetica, Arial, sans-serif;font-size: 15px;text-align: start;white-space: normal;"><span style="font-size: 15px;">考虑到 “Clear Architecture” 的教训，你还应该保护你的业务逻辑。将各种 Spring Boot 代码混合在一起是非常诱人的…… 不要这样做。如果你能抵制诱惑，你将保持你的业务逻辑可重用。</span></p> <p style="box-sizing: border-box;margin-top: 15px;margin-bottom: 15px;color: rgb(80, 97, 109);font-family: Helvetica, Arial, sans-serif;font-size: 15px;text-align: start;white-space: normal;"><span style="font-size: 15px;">部分服务通常成为库。如果不从代码中删除大量 Spring 注解，则更容易创建。</span></p> <h3 style="box-sizing: border-box;margin-top: 2rem;margin-bottom: 0.5rem;font-weight: 700;color: rgb(255, 140, 0);line-height: 1.35;font-size: 18px;text-align: start;white-space: normal;font-family: Menlo, Monaco, 'Source Code Pro', Consolas, Inconsolata, 'Ubuntu Mono', 'DejaVu Sans Mono', 'Courier New', 'Droid Sans Mono', 'Hiragino Sans GB', 微软雅黑, monospace !important;"><span style="font-size: 15px;color: rgb(123, 12, 0);">10、推荐使用构造函数注入</span></h3> <p style="box-sizing: border-box;margin-top: 15px;margin-bottom: 15px;color: rgb(80, 97, 109);font-family: Helvetica, Arial, sans-serif;font-size: 15px;text-align: start;white-space: normal;"><span style="font-size: 15px;">这一条实践来自 Phil Webb（Spring Boot 的项目负责人, @phillip_webb）。</span></p> <p style="box-sizing: border-box;margin-top: 15px;margin-bottom: 15px;color: rgb(80, 97, 109);font-family: Helvetica, Arial, sans-serif;font-size: 15px;text-align: start;white-space: normal;"><span style="font-size: 15px;">保持业务逻辑免受 Spring Boot 代码侵入的一种方法是使用构造函数注入。不仅是因为</span><code style=""><span style="font-size: 15px;">@Autowired</span></code><span style="font-size: 15px;">注解在构造函数上是可选的，而且还可以在没有 Spring 的情况下轻松实例化 bean。</span></p> <h3 style="box-sizing: border-box;margin-top: 2rem;margin-bottom: 0.5rem;font-weight: 700;color: rgb(255, 140, 0);line-height: 1.35;font-size: 18px;text-align: start;white-space: normal;font-family: Menlo, Monaco, 'Source Code Pro', Consolas, Inconsolata, 'Ubuntu Mono', 'DejaVu Sans Mono', 'Courier New', 'Droid Sans Mono', 'Hiragino Sans GB', 微软雅黑, monospace !important;"><span style="font-size: 15px;color: rgb(123, 12, 0);">11、熟悉并发模型</span></h3> <p style="box-sizing: border-box;margin-top: 15px;margin-bottom: 15px;color: rgb(80, 97, 109);font-family: Helvetica, Arial, sans-serif;font-size: 15px;text-align: start;white-space: normal;"><span style="font-size: 15px;">我写过的最受欢迎的文章之一是 “介绍 Spring Boot 中的并发”。我认为这样做的原因是这个领域经常被误解和忽视。如果使用不当，就会出现问题。</span></p> <blockquote style="box-sizing: border-box;margin-bottom: 1.2em;padding: 15px 15px 15px 1rem;color: rgb(129, 145, 152);border-left-width: 6px;border-left-color: rgb(96, 125, 139);font-size: 14px;line-height: 18px;background: rgb(242, 247, 251);font-family: Helvetica, Arial, sans-serif;text-align: start;white-space: normal;"> <p style="box-sizing: border-box;"><span style="font-size: 15px;">https://www.e4developer.com/2018/03/30/introduction-to-concurrency-in-spring-boot/</span></p> </blockquote> <p style="box-sizing: border-box;margin-top: 15px;margin-bottom: 15px;color: rgb(80, 97, 109);font-family: Helvetica, Arial, sans-serif;font-size: 15px;text-align: start;white-space: normal;"><span style="font-size: 15px;">在 Spring Boot 中，Controller 和 Service 是默认是单例。如果你不小心，这会引入可能的并发问题。你通常也在处理有限的线程池。请熟悉这些概念。</span></p> <p style="box-sizing: border-box;margin-top: 15px;margin-bottom: 15px;color: rgb(80, 97, 109);font-family: Helvetica, Arial, sans-serif;font-size: 15px;text-align: start;white-space: normal;"><span style="font-size: 15px;">如果你正在使用新的 WebFlux 风格的 Spring Boot 应用程序，我已经解释了它在 “Spring’s WebFlux/Reactor Parallelism and Backpressure” 中是如何工作的。</span></p> <h3 style="box-sizing: border-box;margin-top: 2rem;margin-bottom: 0.5rem;font-weight: 700;color: rgb(255, 140, 0);line-height: 1.35;font-size: 18px;text-align: start;white-space: normal;font-family: Menlo, Monaco, 'Source Code Pro', Consolas, Inconsolata, 'Ubuntu Mono', 'DejaVu Sans Mono', 'Courier New', 'Droid Sans Mono', 'Hiragino Sans GB', 微软雅黑, monospace !important;"><span style="font-size: 15px;color: rgb(123, 12, 0);">12、加强配置管理的外部化</span></h3> <p style="box-sizing: border-box;margin-top: 15px;margin-bottom: 15px;color: rgb(80, 97, 109);font-family: Helvetica, Arial, sans-serif;font-size: 15px;text-align: start;white-space: normal;"><span style="font-size: 15px;">这一点超出了 Spring Boot，虽然这是人们开始创建多个类似服务时常见的问题……</span></p> <p style="box-sizing: border-box;margin-top: 15px;margin-bottom: 15px;color: rgb(80, 97, 109);font-family: Helvetica, Arial, sans-serif;font-size: 15px;text-align: start;white-space: normal;"><span style="font-size: 15px;">你可以手动处理 Spring 应用程序的配置。如果你正在处理多个 Spring Boot 应用程序，则需要使配置管理能力更加强大。</span></p> <p style="box-sizing: border-box;margin-top: 15px;margin-bottom: 15px;color: rgb(80, 97, 109);font-family: Helvetica, Arial, sans-serif;font-size: 15px;text-align: start;white-space: normal;"><span style="font-size: 15px;">我推荐两种主要方法：</span></p> <ul style="padding-left: 20px;list-style: square;color: rgb(80, 97, 109);font-family: Helvetica, Arial, sans-serif;font-size: 15px;text-align: start;white-space: normal;margin-top: 2px !important;" class="list-paddingleft-2"> <li style="box-sizing: border-box;margin-top: 2px !important;font-size: 15px;"><p style="box-sizing: border-box;margin-bottom: 15px;"><span style="font-size: 15px;">使用配置服务器，例如 Spring Cloud Config；</span></p></li> <li style="box-sizing: border-box;margin-top: 2px !important;font-size: 15px;"><p style="box-sizing: border-box;margin-bottom: 15px;"><span style="font-size: 15px;">将所有配置存储在环境变量中（可以基于 git 仓库进行配置）。</span></p></li> </ul> <p style="box-sizing: border-box;margin-top: 15px;margin-bottom: 15px;color: rgb(80, 97, 109);font-family: Helvetica, Arial, sans-serif;font-size: 15px;text-align: start;white-space: normal;"><span style="font-size: 15px;">这些选项中的任何一个（第二个选项多一些）都要求你在 DevOps 更少工作量，但这在微服务领域是很常见的。</span></p> <h3 style="box-sizing: border-box;margin-top: 2rem;margin-bottom: 0.5rem;font-weight: 700;color: rgb(255, 140, 0);line-height: 1.35;font-size: 18px;text-align: start;white-space: normal;font-family: Menlo, Monaco, 'Source Code Pro', Consolas, Inconsolata, 'Ubuntu Mono', 'DejaVu Sans Mono', 'Courier New', 'Droid Sans Mono', 'Hiragino Sans GB', 微软雅黑, monospace !important;"><span style="font-size: 15px;color: rgb(123, 12, 0);">13、提供全局异常处理</span></h3> <p style="box-sizing: border-box;margin-top: 15px;margin-bottom: 15px;color: rgb(80, 97, 109);font-family: Helvetica, Arial, sans-serif;font-size: 15px;text-align: start;white-space: normal;"><span style="font-size: 15px;">你真的需要一种处理异常的一致方法。Spring Boot 提供了两种主要方法：</span></p> <ul style="padding-left: 20px;list-style: square;color: rgb(80, 97, 109);font-family: Helvetica, Arial, sans-serif;font-size: 15px;text-align: start;white-space: normal;margin-top: 2px !important;" class="list-paddingleft-2"> <li style="box-sizing: border-box;margin-top: 2px !important;font-size: 15px;"><p style="box-sizing: border-box;margin-bottom: 15px;"><span style="font-size: 15px;">你应该使用 HandlerExceptionResolver 定义全局异常处理策略；</span></p></li> <li style="box-sizing: border-box;margin-top: 2px !important;font-size: 15px;"><p style="box-sizing: border-box;margin-bottom: 15px;"><span style="font-size: 15px;">你也可以在控制器上添加 @ExceptionHandler 注解，这在某些特定场景下使用可能会很有用。</span></p></li> </ul> <p style="box-sizing: border-box;margin-top: 15px;margin-bottom: 15px;color: rgb(80, 97, 109);font-family: Helvetica, Arial, sans-serif;font-size: 15px;text-align: start;white-space: normal;"><span style="font-size: 15px;">这与 Spring 中的几乎相同，并且 Baeldung 有一篇关于 REST 与 Spring 的错误处理的详细文章，非常值得一读。</span></p> <blockquote style="box-sizing: border-box;margin-bottom: 1.2em;padding: 15px 15px 15px 1rem;color: rgb(129, 145, 152);border-left-width: 6px;border-left-color: rgb(96, 125, 139);font-size: 14px;line-height: 18px;background: rgb(242, 247, 251);font-family: Helvetica, Arial, sans-serif;text-align: start;white-space: normal;"> <p style="box-sizing: border-box;"><span style="font-size: 15px;">https://www.baeldung.com/exception-handling-for-rest-with-spring</span></p> </blockquote> <h3 style="box-sizing: border-box;margin-top: 2rem;margin-bottom: 0.5rem;font-weight: 700;color: rgb(255, 140, 0);line-height: 1.35;font-size: 18px;text-align: start;white-space: normal;font-family: Menlo, Monaco, 'Source Code Pro', Consolas, Inconsolata, 'Ubuntu Mono', 'DejaVu Sans Mono', 'Courier New', 'Droid Sans Mono', 'Hiragino Sans GB', 微软雅黑, monospace !important;"><span style="font-size: 15px;color: rgb(123, 12, 0);">14、使用日志框架</span></h3> <p style="box-sizing: border-box;margin-top: 15px;margin-bottom: 15px;color: rgb(80, 97, 109);font-family: Helvetica, Arial, sans-serif;font-size: 15px;text-align: start;white-space: normal;"><span style="font-size: 15px;">你可能已经意识到这一点，但你应该使用 Logger 进行日志记录，而不是使用 System.out.println() 手动执行。这很容易在 Spring Boot 中完成，几乎没有配置。只需获取该类的记录器实例：</span></p> <pre style="box-sizing: border-box;padding: 0.5em;font-family: Courier, 'Courier New', monospace;background: rgb(45, 45, 45);border-width: 1px;border-style: solid;border-color: rgb(221, 221, 221);overflow-x: auto;color: rgb(204, 204, 204);font-size: 15px;text-align: start;"><code style=""><span style="font-size: 15px;">Logger&nbsp;logger&nbsp;=&nbsp;LoggerFactory.getLogger(MyClass.class);<br></span></code></pre> <p style="box-sizing: border-box;margin-top: 15px;margin-bottom: 15px;color: rgb(80, 97, 109);font-family: Helvetica, Arial, sans-serif;font-size: 15px;text-align: start;white-space: normal;"><span style="font-size: 15px;">这很重要，因为它可以让你根据需要设置不同的日志记录级别。</span></p> <h3 style="box-sizing: border-box;margin-top: 2rem;margin-bottom: 0.5rem;font-weight: 700;color: rgb(255, 140, 0);line-height: 1.35;font-size: 18px;text-align: start;white-space: normal;font-family: Menlo, Monaco, 'Source Code Pro', Consolas, Inconsolata, 'Ubuntu Mono', 'DejaVu Sans Mono', 'Courier New', 'Droid Sans Mono', 'Hiragino Sans GB', 微软雅黑, monospace !important;"><span style="font-size: 15px;color: rgb(123, 12, 0);">15、测试你的代码</span></h3> <p style="box-sizing: border-box;margin-top: 15px;margin-bottom: 15px;color: rgb(80, 97, 109);font-family: Helvetica, Arial, sans-serif;font-size: 15px;text-align: start;white-space: normal;"><span style="font-size: 15px;">这不是 Spring Boot 特有的，但它需要提醒——测试你的代码！如果你没有编写测试，那么你将从一开始就编写遗留代码。</span></p> <p style="box-sizing: border-box;margin-top: 15px;margin-bottom: 15px;color: rgb(80, 97, 109);font-family: Helvetica, Arial, sans-serif;font-size: 15px;text-align: start;white-space: normal;"><span style="font-size: 15px;">如果有其他人使用你的代码库，那边改变任何东西将会变得危险。当你有多个服务相互依赖时，这甚至可能更具风险。</span></p> <p style="box-sizing: border-box;margin-top: 15px;margin-bottom: 15px;color: rgb(80, 97, 109);font-family: Helvetica, Arial, sans-serif;font-size: 15px;text-align: start;white-space: normal;"><span style="font-size: 15px;">由于存在 Spring Boot 最佳实践，因此你应该考虑将 Spring Cloud Contract 用于你的消费者驱动契约，它将使你与其他服务的集成更容易使用。</span></p> <h3 style="box-sizing: border-box;margin-top: 2rem;margin-bottom: 0.5rem;font-weight: 700;color: rgb(255, 140, 0);line-height: 1.35;font-size: 18px;text-align: start;white-space: normal;font-family: Menlo, Monaco, 'Source Code Pro', Consolas, Inconsolata, 'Ubuntu Mono', 'DejaVu Sans Mono', 'Courier New', 'Droid Sans Mono', 'Hiragino Sans GB', 微软雅黑, monospace !important;"><span style="font-size: 15px;color: rgb(123, 12, 0);">16、使用测试切片让测试更容易，并且更专注</span></h3> <p style="box-sizing: border-box;margin-top: 15px;margin-bottom: 15px;color: rgb(80, 97, 109);font-family: Helvetica, Arial, sans-serif;font-size: 15px;text-align: start;white-space: normal;"><span style="font-size: 15px;">这一条实践来自 Madhura Bhave（Spring 开发者, @madhurabhave23）。</span></p> <p style="box-sizing: border-box;margin-top: 15px;margin-bottom: 15px;color: rgb(80, 97, 109);font-family: Helvetica, Arial, sans-serif;font-size: 15px;text-align: start;white-space: normal;"><span style="font-size: 15px;">使用 Spring Boot 测试代码可能很棘手——你需要初始化数据层，连接大量服务，模拟事物…… 实际上并不是那么难！答案是使用测试切片。</span></p> <p style="box-sizing: border-box;margin-top: 15px;margin-bottom: 15px;color: rgb(80, 97, 109);font-family: Helvetica, Arial, sans-serif;font-size: 15px;text-align: start;white-space: normal;"><span style="font-size: 15px;">使用测试切片，你可以根据需要仅连接部分应用程序。这可以为你节省大量时间，并确保你的测试不会与未使用的内容相关联。来自 spring.io 的一篇名为 Custom test slice with Spring test 1.4 的博客文章解释了这种技术。</span></p> <blockquote style="box-sizing: border-box;margin-bottom: 1.2em;padding: 15px 15px 15px 1rem;color: rgb(129, 145, 152);border-left-width: 6px;border-left-color: rgb(96, 125, 139);font-size: 14px;line-height: 18px;background: rgb(242, 247, 251);font-family: Helvetica, Arial, sans-serif;text-align: start;white-space: normal;"> <p style="box-sizing: border-box;"><span style="font-size: 15px;">https://spring.io/blog/2016/08/30/custom-test-slice-with-spring-boot-1-4</span></p> </blockquote> <h3 style="box-sizing: border-box;margin-top: 2rem;margin-bottom: 0.5rem;font-weight: 700;color: rgb(255, 140, 0);line-height: 1.35;font-size: 18px;text-align: start;white-space: normal;font-family: Menlo, Monaco, 'Source Code Pro', Consolas, Inconsolata, 'Ubuntu Mono', 'DejaVu Sans Mono', 'Courier New', 'Droid Sans Mono', 'Hiragino Sans GB', 微软雅黑, monospace !important;"><span style="font-size: 15px;color: rgb(123, 12, 0);">总结</span></h3> <p style="box-sizing: border-box;margin-top: 15px;margin-bottom: 15px;color: rgb(80, 97, 109);font-family: Helvetica, Arial, sans-serif;font-size: 15px;text-align: start;white-space: normal;"><span style="font-size: 15px;">感谢 Spring Boot，编写基于 Spring 的微服务正变得前所未有的简单。我希望通过这些最佳实践，你的实施过程不仅会变得很快，而且从长远来看也会更加强大和成功。祝你好运！</span></p> <p style="box-sizing: border-box;margin-top: 15px;margin-bottom: 15px;color: rgb(80, 97, 109);font-family: Helvetica, Arial, sans-serif;font-size: 15px;text-align: start;white-space: normal;"><span style="font-size: 15px;"><br></span></p> <section data-mpa-template="t" mpa-from-tpl="t" style="font-family: -apple-system-font, system-ui, &quot;Helvetica Neue&quot;, &quot;PingFang SC&quot;, &quot;Hiragino Sans GB&quot;, &quot;Microsoft YaHei UI&quot;, &quot;Microsoft YaHei&quot;, Arial, sans-serif;letter-spacing: 0.544px;white-space: normal;background-color: rgb(255, 255, 255);font-size: 16px;text-align: left;color: rgb(120, 114, 114);widows: 1;word-spacing: 2px;"> <section data-id="89429" mpa-from-tpl="t" style="border-width: 0px;border-style: none;border-color: initial;"> <section mpa-from-tpl="t" style="text-align: center;height: 50px;"> <section mpa-from-tpl="t" style="margin-right: auto;margin-left: auto;width: 48px;height: 48px;color: rgb(255, 255, 255);line-height: 48px;display: inline-block;background-image: url(&quot;https://mmbiz.qpic.cn/mmbiz_gif/kiaqiahsnxHd4Zt4378tqib1DnnfKYvZAI7sUNZCYmGN2HCMDFDYV5hLu6HrHIK5BynAAwgHGiafFFU7ibYez6mXL4w/640?wx_fmt=gif&quot;);background-repeat: 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&quot;Microsoft YaHei&quot;, Arial, sans-serif;font-size: 15px;widows: 1;word-spacing: 2px;text-align: right;"><img class="rich_pages" data-ratio="0.5555555555555556" data-s="300,640" data-type="jpeg" data-w="900" src="/upload/9d786e52e671b1ce4beb338d1e0d1815.jpg" style="letter-spacing: 0.544px;text-align: center;font-family: mp-quote, -apple-system-font, BlinkMacSystemFont, &quot;Helvetica Neue&quot;, &quot;PingFang SC&quot;, &quot;Hiragino Sans GB&quot;, &quot;Microsoft YaHei UI&quot;, &quot;Microsoft YaHei&quot;, Arial, sans-serif;box-sizing: border-box !important;visibility: visible !important;width: 677px !important;"><span style="letter-spacing: 0.544px;font-size: 14px;">如有收获，点个在看，诚挚感谢</span><img data-ratio="1" data-type="png" data-w="19" width="19px" src="/upload/5f7454d24a334e968c32b8ce9ae53c5.png" style="font-size: 16px;letter-spacing: 0.544px;display: inline-block;vertical-align: text-bottom;box-sizing: border-box !important;visibility: visible !important;width: 19px !important;"></p> <p style="box-sizing: border-box;margin-top: 15px;margin-bottom: 15px;color: rgb(80, 97, 109);font-family: Helvetica, Arial, sans-serif;font-size: 15px;text-align: start;white-space: normal;"><br></p> <pre style="background-color: rgb(255, 255, 255);font-size: 15px;letter-spacing: 0.544px;text-align: start;color: rgb(62, 62, 62);widows: 1;word-spacing: 1px;caret-color: rgb(51, 51, 51);"></pre>

<section style="box-sizing: border-box;font-style: normal;font-weight: 400;text-align: justify;font-size: 16px;"> <section style="margin-top: 10px;margin-bottom: 10px;box-sizing: border-box;"> <section style="padding: 10px 10px 0px;background-color: rgb(239, 239, 239);box-sizing: border-box;"> <span style="display: inline-block;width: 5%;line-height: 0.8;font-weight: bolder;font-size: 48px;box-sizing: border-box;" title=""> <section style="box-sizing: border-box;"> “ </section></span> <section style="display: inline-block;vertical-align: top;float: right;width: 90%;line-height: 1.5;font-size: 15px;color: rgb(89, 89, 89);box-sizing: border-box;"> <p style="margin: 0px;padding: 0px;box-sizing: border-box;"><span style="letter-spacing: 1px;">最近几年微服务很火，大家都在建设微服务，如果不懂点微服务相关的技术，都不好意思跟同行打招呼了。</span></p> </section> <section style="clear: both;box-sizing: border-box;"> <svg viewbox="0 0 1 1" style="float:left;line-height:0;width:0;vertical-align:top;"></svg> </section> </section> </section> </section> <p style="line-height: 1.75em;"><br></p> <section style="text-align: center;margin-left: 8px;margin-right: 8px;"> <img class="rich_pages" data-ratio="0.6592741935483871" data-s="300,640" src="/upload/5333f9788dc79b04dd350883eceba4d2.png" data-type="png" data-w="992" style=""> </section> <section style="text-align: center;line-height: 1.75em;"> <span style="font-size: 14px;color: rgb(89, 89, 89);letter-spacing: 1px;"><em>图片来自 Pexels</em></span> <br> </section> <section style="line-height: normal;"> <br> </section> <p style="text-align: justify;margin-left: 8px;margin-right: 8px;line-height: 1.75em;"><span style="font-size: 15px;color: rgb(89, 89, 89);letter-spacing: 1px;">我也见过身边很多人在微服务踩过很多坑，我从 2016 年开始接触微服务，有多家大型企业的微服务分布式系统的架构经验，不过微服务和涉及的分布式计算非常的复杂，绝非是一篇文章就可以讲清楚的。<br></span></p> <section style="line-height: normal;"> <br> </section> <p style="text-align: justify;margin-left: 8px;margin-right: 8px;line-height: 1.75em;"><span style="font-size: 15px;color: rgb(89, 89, 89);letter-spacing: 1px;">本文只是从最简单的概念的基本使用带你入门，如果后续还有兴趣的话，可以查阅相关的文献和技术书籍去深入学习。</span></p> <section style="line-height: normal;"> <br> </section> <p style="text-align: justify;margin-left: 8px;margin-right: 8px;line-height: 1.75em;"><span style="font-size: 15px;letter-spacing: 1px;color: rgb(71, 193, 168);">本文的微服务分享以下三部分，总体大纲如下：</span></p> <ul style="list-style-type: disc;" class="list-paddingleft-2"> <li style="font-weight: bold;"> <section style="line-height: 1.75em;"> <strong><span style="font-size: 15px;color: rgb(89, 89, 89);letter-spacing: 1px;">微服务的概念和原则（理论）</span></strong> </section></li> <li style="font-weight: bold;"> <section style="line-height: 1.75em;"> <strong><span style="font-size: 15px;color: rgb(89, 89, 89);letter-spacing: 1px;">Spring Cloud 如何低成本的实现微服务（实现）</span></strong> </section></li> <li style="font-weight: bold;"> <section style="line-height: 1.75em;"> <strong><span style="font-size: 15px;color: rgb(89, 89, 89);letter-spacing: 1px;">Spring Cloud 大型项目的架构方案（真实案例）</span></strong> </section></li> </ul> <p style="line-height: normal;"><br></p> <section> <section> <section> <section style="box-sizing: border-box;font-style: normal;font-weight: 400;text-align: justify;font-size: 16px;"> <section style="border-bottom: 1px solid black;margin: 0.5em 0px;line-height: 1.2;box-sizing: border-box;"> <section style="display: inline-block;border-color: rgb(89, 89, 89);border-bottom: 6px solid rgb(89, 89, 89);margin-bottom: -1px;font-size: 20px;color: rgb(89, 89, 89);box-sizing: border-box;"> <p style="margin: 0px;padding: 0px;box-sizing: border-box;">微服务的概念和原则<br></p> </section> </section> </section> </section> </section> </section> <section> <section> <section> <section> <section> <section style="line-height: normal;"> <br> </section> <section> <section> <section> <section style="box-sizing: border-box;font-style: normal;font-weight: 400;text-align: justify;font-size: 16px;"> <section style="margin-top: 10px;margin-bottom: 10px;box-sizing: border-box;"> <section style="width: 0.6em;display: inline-block;vertical-align: middle;box-sizing: border-box;"> <span style="width: 0.6em;height: 0.6em;display: block;opacity: 0.2;background-color: rgb(89, 89, 89);box-sizing: border-box;"></span> <span style="width: 0.6em;height: 0.6em;display: block;opacity: 0.6;margin: 2px 0px;background-color: rgb(89, 89, 89);box-sizing: border-box;"></span> <strong><span style="width: 0.6em;height: 0.6em;display: block;opacity: 1;background-color: rgb(89, 89, 89);box-sizing: border-box;"></span> </strong> </section> <section style="display: inline-block;vertical-align: middle;font-size: 18px;padding-left: 5px;color: rgb(89, 89, 89);box-sizing: border-box;"> <p style="margin: 0px;padding: 0px;box-sizing: border-box;"><strong>什么是微服务？</strong></p> </section> </section> </section> <p style="line-height: normal;"><br></p> </section> </section> </section> </section> </section> </section> </section> </section> <h5 style="text-align: justify;margin-left: 8px;margin-right: 8px;line-height: 1.75em;"><strong><span style="font-size: 15px;color: rgb(89, 89, 89);letter-spacing: 1px;">简单举例：</span></strong><span style="font-size: 15px;color: rgb(89, 89, 89);letter-spacing: 1px;">看军事新闻的同学应该都知道，一艘航空母舰作战能力虽然很强，但是弱点太明显，就是防御能力太差，单艘的航空母舰很少单独行动，通常航空母舰战斗群才是主要军事力量。</span></h5> <h5 style="line-height: normal;"><br></h5> <h5 style="text-align: justify;margin-left: 8px;margin-right: 8px;line-height: 1.75em;"><span style="font-size: 15px;color: rgb(89, 89, 89);letter-spacing: 1px;">你可以把单艘航母理解为的单体应用（防御差，机动性不好），把航母战斗群（调度复杂，维护费用高）理解为微服务。</span></h5> <p style="line-height: normal;"><br></p> <section style="text-align: justify;margin-left: 8px;margin-right: 8px;line-height: 1.75em;"> <span style="font-size: 15px;letter-spacing: 1px;color: rgb(71, 193, 168);">简单讲特征就是：</span> </section> <ul style="list-style-type: disc;" class="list-paddingleft-2"> <li> <section style="line-height: 1.75em;"> <strong><span style="font-size: 15px;color: rgb(89, 89, 89);letter-spacing: 1px;">单体应用：</span></strong> <span style="font-size: 15px;color: rgb(89, 89, 89);letter-spacing: 1px;">简单，脆弱（某个模块出问题，整个系统不可用），战斗力弱，维护成本低。</span> </section></li> <li> <section style="margin-bottom: 5px;line-height: 1.75em;"> <strong><span style="font-size: 15px;color: rgb(89, 89, 89);letter-spacing: 1px;">微服务架构：</span></strong> <span style="font-size: 15px;color: rgb(89, 89, 89);letter-spacing: 1px;">复杂，健壮（某个模块出问题，不会影响系统整体的可用性），战斗力强，维护成本高。</span> <br> </section></li> </ul> <p style="text-align: center;margin-left: 8px;margin-right: 8px;margin-bottom: 5px;"><img class="rich_pages" data-ratio="0.75" data-s="300,640" src="/upload/a422e69baf4a96ae0d0820c664d13822.jpg" data-type="jpeg" data-w="1080" style=""></p> <section style="text-align: center;margin-left: 8px;margin-right: 8px;line-height: 1.75em;margin-bottom: 5px;"> <span style="font-size: 14px;"><em><span style="color: rgb(89, 89, 89);letter-spacing: 1px;">单体作战的应用（图）</span></em></span> <br> </section> <p style="text-align: center;margin-left: 8px;margin-right: 8px;margin-bottom: 5px;"><img class="rich_pages" data-ratio="0.5138888888888888" data-s="300,640" src="/upload/e8f8915538f18035c174dd56b7ecc790.jpg" data-type="jpeg" data-w="1080" style=""></p> <section style="text-align: center;margin-left: 8px;margin-right: 8px;line-height: 1.75em;"> <span style="font-size: 14px;"><em><span style="color: rgb(89, 89, 89);letter-spacing: 1px;">微服务战斗群（图）</span></em></span> <br> </section> <section style="line-height: normal;"> <br> </section> <p style="text-align: justify;margin-left: 8px;margin-right: 8px;line-height: 1.75em;"><span style="font-size: 15px;color: rgb(89, 89, 89);letter-spacing: 1px;">大部分的开发者经历和开发过单体应用，无论是传统的 SSM，还是现在的 Spring Boot/Rails，它们都是单体应用。<br></span></p> <p style="line-height: normal;"><br></p> <p style="text-align: justify;margin-left: 8px;margin-right: 8px;line-height: 1.75em;"><span style="font-size: 15px;color: rgb(89, 89, 89);letter-spacing: 1px;">那么长期陪伴我们的单体应用有什么弊端？我们是面临了什么问题，导致我们要抛弃单体应用转向微服务架构？<br></span></p> <section style="line-height: normal;"> <br> </section> <p style="text-align: justify;margin-left: 8px;margin-right: 8px;line-height: 1.75em;"><span style="font-size: 15px;letter-spacing: 1px;color: rgb(71, 193, 168);">个人总结主要问题如下：</span></p> <ul style="list-style-type: disc;" class="list-paddingleft-2"> <li><p style="line-height: 1.75em;"><span style="font-size: 15px;color: rgb(89, 89, 89);letter-spacing: 1px;">部署成本高（无论是修改 1 行代码，还是 10 行代码，都要全量部署替换）。</span></p></li> <li><p style="line-height: 1.75em;"><span style="font-size: 15px;color: rgb(89, 89, 89);letter-spacing: 1px;">改动影响大，风险高，测试成本高（不论代码改动多小，成本都相同）。</span></p></li> <li><p style="line-height: 1.75em;"><span style="font-size: 15px;color: rgb(89, 89, 89);letter-spacing: 1px;">因为成本高，风险高，所以导致部署频率低（无法满足快速交付客户需求）。</span></p></li> </ul> <section style="line-height: normal;"> <br> </section> <section style="text-align: justify;margin-left: 8px;margin-right: 8px;line-height: 1.75em;margin-bottom: 5px;"> <span style="font-size: 15px;color: rgb(89, 89, 89);letter-spacing: 1px;">当然还有例如无法满足快速扩容，弹性伸缩，无法适应云环境特性等问题，但我们不一一详谈了，以上的问题，都是微服务架构要解决的问题，至于具体是怎么解决的，我们先放到后面再聊。</span> <br> </section> <section style="text-align: center;margin-bottom: 5px;margin-left: 8px;margin-right: 8px;"> <img class="rich_pages" data-ratio="0.5166666666666667" data-s="300,640" src="/upload/e408a037705ab403d9d19edf9ef1a917.jpg" data-type="jpeg" data-w="1080" style=""> </section> <section style="text-align: center;margin-left: 8px;margin-right: 8px;line-height: 1.75em;"> <span style="font-size: 14px;letter-spacing: 1px;"><em><span style="color: rgb(89, 89, 89);">历代应用程序的架构变迁（图）</span></em></span> <br> </section> <p style="line-height: normal;"><br></p> <section> <section> <section> <section> <section> <section> <section> <section style="box-sizing: border-box;font-style: normal;font-weight: 400;text-align: justify;font-size: 16px;"> <section style="margin-top: 10px;margin-bottom: 10px;box-sizing: border-box;"> <section style="width: 0.6em;display: inline-block;vertical-align: middle;box-sizing: border-box;"> <span style="width: 0.6em;height: 0.6em;display: block;opacity: 0.2;background-color: rgb(89, 89, 89);box-sizing: border-box;"></span> <span style="width: 0.6em;height: 0.6em;display: block;opacity: 0.6;margin: 2px 0px;background-color: rgb(89, 89, 89);box-sizing: border-box;"></span> <strong><span style="width: 0.6em;height: 0.6em;display: block;opacity: 1;background-color: rgb(89, 89, 89);box-sizing: border-box;"></span> </strong> </section> <section style="display: inline-block;vertical-align: middle;font-size: 18px;padding-left: 5px;color: rgb(89, 89, 89);box-sizing: border-box;"> <p style="margin: 0px;padding: 0px;box-sizing: border-box;"><strong>解决什么问题，又引入了什么问题？</strong></p> </section> </section> </section> <p style="line-height: normal;"><br></p> </section> </section> </section> </section> </section> </section> </section> <h5 style="text-align: justify;margin-left: 8px;margin-right: 8px;line-height: 1.75em;"><span style="font-size: 15px;letter-spacing: 1px;color: rgb(71, 193, 168);">我们先看看微服务能带给我们什么？微服务架构的特点：</span></h5> <ul style="list-style-type: disc;" class="list-paddingleft-2"> <li><h5 style="text-align: justify;margin-left: 8px;margin-right: 8px;line-height: 1.75em;"><strong><span style="font-size: 15px;color: rgb(89, 89, 89);letter-spacing: 1px;">针对特定服务发布，影响小，风险小，成本低</span></strong></h5></li> <li><h5 style="text-align: justify;margin-left: 8px;margin-right: 8px;line-height: 1.75em;"><strong><span style="font-size: 15px;color: rgb(89, 89, 89);letter-spacing: 1px;">频繁发布版本，快速交付需求</span></strong></h5></li> <li><h5 style="text-align: justify;margin-left: 8px;margin-right: 8px;line-height: 1.75em;"><strong><span style="font-size: 15px;color: rgb(89, 89, 89);letter-spacing: 1px;">低成本扩容，弹性伸缩，适应云环境</span></strong></h5></li> </ul> <section style="line-height: normal;"> <br> </section> <p style="text-align: justify;margin-left: 8px;margin-right: 8px;line-height: 1.75em;"><span style="font-size: 15px;color: rgb(89, 89, 89);letter-spacing: 1px;">我们知道一个朴素的理念，没有任何事物是完美的，任何东西都有两面性，有得必有失。<br></span></p> <section style="line-height: normal;"> <br> </section> <p style="text-align: justify;margin-left: 8px;margin-right: 8px;line-height: 1.75em;"><span style="font-size: 15px;color: rgb(89, 89, 89);letter-spacing: 1px;">那么在选择微服务在解决了快速响应和弹性伸缩的问题同时，它又给我们带来了什么问题？</span></p> <section style="line-height: normal;"> <br> </section> <p style="text-align: justify;margin-left: 8px;margin-right: 8px;line-height: 1.75em;"><span style="font-size: 15px;letter-spacing: 1px;color: rgb(71, 193, 168);">个人总结如下：</span></p> <ul style="list-style-type: disc;" class="list-paddingleft-2"> <li style="font-weight: bold;"> <section style="text-align: justify;margin-left: 8px;margin-right: 8px;line-height: 1.75em;"> <strong><span style="font-size: 15px;color: rgb(89, 89, 89);letter-spacing: 1px;">分布式系统的复杂性</span></strong> </section></li> <li style="font-weight: bold;"> <section style="text-align: justify;margin-left: 8px;margin-right: 8px;line-height: 1.75em;"> <strong><span style="font-size: 15px;color: rgb(89, 89, 89);letter-spacing: 1px;">部署，测试和监控的成本问题</span></strong> </section></li> <li style="font-weight: bold;"> <section style="text-align: justify;margin-left: 8px;margin-right: 8px;line-height: 1.75em;"> <strong><span style="font-size: 15px;color: rgb(89, 89, 89);letter-spacing: 1px;">分布式事务和 CAP 的相关问题</span></strong> </section></li> </ul> <section style="line-height: normal;"> <br> </section> <p style="text-align: justify;margin-left: 8px;margin-right: 8px;line-height: 1.75em;"><span style="font-size: 15px;color: rgb(89, 89, 89);letter-spacing: 1px;">系统应用由原来的单体变成几十到几百个不同的工程，会所产生例如包括服务间的依赖，服务如何拆封，内部接口规范，数据传递等等问题。<br></span></p> <section style="line-height: normal;"> <br> </section> <p style="text-align: justify;margin-left: 8px;margin-right: 8px;line-height: 1.75em;"><span style="font-size: 15px;color: rgb(89, 89, 89);letter-spacing: 1px;">尤其是服务拆分，需要团队熟悉业务流程，懂得取舍，要保证拆分的粒度服务既符合“高内聚，低耦合”的基本原则，还要兼顾业务的发展以及公司的愿景，要还要说服团队成员为之努力，并且积极投入，在多方中间取得平衡。<br></span></p> <section style="line-height: normal;"> <br> </section> <p style="text-align: justify;margin-left: 8px;margin-right: 8px;line-height: 1.75em;"><span style="font-size: 15px;color: rgb(89, 89, 89);letter-spacing: 1px;">对于分布式系统，部署，测试和监控都需要大量的中间件来支撑，而且中间件本身也要维护。<br></span></p> <section style="line-height: normal;"> <br> </section> <p style="text-align: justify;margin-left: 8px;margin-right: 8px;line-height: 1.75em;"><span style="font-size: 15px;color: rgb(89, 89, 89);letter-spacing: 1px;">原先单体应用很简单的事务问题 ，转到分布式环境就变得很复杂，分布式事务是采用简单的重试+补偿机制，还是采用二阶段提交协议等强一致性方法来解决，就要取决对业务场景的熟悉加上反复的权衡了。<br></span></p> <section style="line-height: normal;"> <br> </section> <section style="text-align: justify;margin-left: 8px;margin-right: 8px;line-height: 1.75em;margin-bottom: 5px;"> <span style="font-size: 15px;color: rgb(89, 89, 89);letter-spacing: 1px;">相同问题还包括对 CAP 模型的权衡，总之微服务对团队整体的技术栈水平整体要求更高。<br></span> </section> <p style="text-align: center;margin-bottom: 5px;margin-left: 8px;margin-right: 8px;"><img class="rich_pages" data-ratio="0.388" data-s="300,640" src="/upload/ea43e5073842a1894fc88422a0900d5f.jpg" data-type="jpeg" data-w="1000" style=""></p> <section> <section> <section> <section> <section> <section> <section> <section> <section> <section style="box-sizing: border-box;font-style: normal;font-weight: 400;text-align: justify;font-size: 16px;"> <section style="margin-top: 10px;margin-bottom: 10px;box-sizing: border-box;"> <section style="width: 0.6em;display: inline-block;vertical-align: middle;box-sizing: border-box;"> <span style="width: 0.6em;height: 0.6em;display: block;opacity: 0.2;background-color: rgb(89, 89, 89);box-sizing: border-box;"></span> <span style="width: 0.6em;height: 0.6em;display: block;opacity: 0.6;margin: 2px 0px;background-color: rgb(89, 89, 89);box-sizing: border-box;"></span> <span style="width: 0.6em;height: 0.6em;display: block;opacity: 1;background-color: rgb(89, 89, 89);box-sizing: border-box;"></span> </section> <section style="display: inline-block;vertical-align: middle;font-size: 18px;padding-left: 5px;color: rgb(89, 89, 89);box-sizing: border-box;"> <p style="margin: 0px;padding: 0px;box-sizing: border-box;"><strong>微服务有哪些应该遵循哪些原则？</strong></p> </section> </section> </section> <section style="line-height: normal;"> <br> </section> </section> </section> </section> </section> </section> </section> <p style="text-align: justify;margin-left: 8px;margin-right: 8px;line-height: 1.75em;"><span style="font-size: 15px;color: rgb(89, 89, 89);letter-spacing: 1px;">古人云：兵马未动，粮草先行。建设微服务是需要建立长远规划，不是像写 CMS 那样建好数据库表，然后就开始干活，这样十有八九是会失败的。<br></span></p> <section style="line-height: normal;"> <br> </section> <p style="text-align: justify;margin-left: 8px;margin-right: 8px;line-height: 1.75em;"><span style="font-size: 15px;color: rgb(89, 89, 89);letter-spacing: 1px;">我们要进行微服务改造前，架构师要提前做好规划，我们把这里分为三步，前期阶段，设计阶段，技术阶段。</span><br></p> <section style="line-height: normal;"> <br> </section> </section> </section> </section> <section style="text-align: justify;margin-left: 8px;margin-right: 8px;line-height: 1.75em;"> <span style="font-size: 15px;letter-spacing: 1px;color: rgb(71, 193, 168);">前期阶段，大致要做好如下事情：</span> </section> <ul style="list-style-type: disc;" class="list-paddingleft-2"> <li> <section style="line-height: 1.75em;"> <span style="font-size: 15px;color: rgb(89, 89, 89);letter-spacing: 1px;">和多方充分沟通，确保能符合客户和组织的需求，并且得到认同。</span> </section></li> <li> <section style="line-height: 1.75em;"> <span style="font-size: 15px;color: rgb(89, 89, 89);letter-spacing: 1px;">和团队沟通，让队友（开发/测试/运维）理解，并且积极投入。</span> </section></li> <li> <section style="line-height: 1.75em;"> <span style="font-size: 15px;color: rgb(89, 89, 89);letter-spacing: 1px;">和业务部门沟通，指定版本计划和上线时间。</span> </section></li> </ul> <section style="line-height: normal;"> <br> </section> <p style="text-align: justify;margin-left: 8px;margin-right: 8px;line-height: 1.75em;"><span style="font-size: 15px;color: rgb(89, 89, 89);letter-spacing: 1px;">设计阶段，参考 Sam Newman 的著作《微服务设计》，单微服务必须要满足以下的条件，</span><span style="font-size: 15px;letter-spacing: 1px;color: rgb(71, 193, 168);">才符合微服务的基本要求：</span></p> <ul style="list-style-type: disc;" class="list-paddingleft-2"> <li> <section style="line-height: 1.75em;"> <span style="font-size: 15px;color: rgb(89, 89, 89);letter-spacing: 1px;">标准的 REST 风格接口（基于 HTTP 和 JSON 格式）。</span> </section></li> <li> <section style="line-height: 1.75em;"> <span style="font-size: 15px;color: rgb(89, 89, 89);letter-spacing: 1px;">独立部署，避免共享数据库（避免因为数据库而影响整个分布式系统）。</span> </section></li> <li> <section style="line-height: 1.75em;"> <span style="font-size: 15px;color: rgb(89, 89, 89);letter-spacing: 1px;">业务上的高内聚，减少依赖（从设计上要避免服务过大或者太小）。</span> </section></li> </ul> <p style="text-align: justify;line-height: normal;"><br></p> <section style="text-align: justify;margin-left: 8px;margin-right: 8px;line-height: 1.75em;"> <span style="font-size: 15px;letter-spacing: 1px;color: rgb(71, 193, 168);">庞大的分布式系统，需要强大基础设施来支撑，微服务涉及哪些基础设施？</span> </section> <ul style="list-style-type: disc;" class="list-paddingleft-2"> <li> <section style="line-height: 1.75em;"> <span style="font-size: 15px;color: rgb(89, 89, 89);letter-spacing: 1px;">CI/CD 和自动化（分布式系统几乎不可能通过人工手动发布。）</span> </section></li> <li> <section style="line-height: 1.75em;"> <span style="font-size: 15px;color: rgb(89, 89, 89);letter-spacing: 1px;">虚拟化技术（要保证微服务运行环境隔离，目前行业主流的是使用 Docker 容器）。</span> </section></li> <li> <section style="line-height: 1.75em;"> <span style="font-size: 15px;color: rgb(89, 89, 89);letter-spacing: 1px;">日志聚合，全链路监控（高度可观察和分析诊断问题）。</span> </section></li> </ul> <section style="line-height: normal;"> <br> </section> <p style="text-align: justify;margin-left: 8px;margin-right: 8px;line-height: 1.75em;"><span style="font-size: 15px;letter-spacing: 1px;color: rgb(71, 193, 168);">说了那么多，那什么样的情况下，你的团队不适合建设微服务？（请勿对号入座）</span></p> <ul style="list-style-type: disc;" class="list-paddingleft-2"> <li> <section style="line-height: 1.75em;"> <span style="font-size: 15px;color: rgb(89, 89, 89);letter-spacing: 1px;">开发团队不具备自主性，所在组织对开发团队限制非常多（具体请参考 康威定律）。</span> </section></li> <li> <section style="line-height: 1.75em;"> <span style="font-size: 15px;color: rgb(89, 89, 89);letter-spacing: 1px;">团队不熟悉业务，无法识别出服务的边界，进行合理的拆分（请参考 DDD 领域驱动设计）。</span> </section></li> </ul> <section style="line-height: normal;"> <br> </section> <p style="margin-left: 8px;margin-right: 8px;line-height: 1.75em;"><span style="font-size: 15px;color: rgb(89, 89, 89);letter-spacing: 1px;">微服务设计其实是很早就有的设计思想，因为随着虚拟化技术的崛起，微服务可以低成本的实现，所以也开始流行和兴起。<br></span></p> <section style="line-height: normal;"> <br> </section> <p style="margin-left: 8px;margin-right: 8px;line-height: 1.75em;"><span style="font-size: 15px;color: rgb(89, 89, 89);letter-spacing: 1px;">微服务的内涵很深，其中就包括，自动化，去中心化，独立性等等，其中细节无法用一篇文章概述清楚，我们在做技术选型或者方案的时候，尽可能多去了解技术的本身和起源再结合我们业务的特点，进行更好的选择。</span></p> <p style="line-height: normal;"><br></p> <section style="box-sizing: border-box;font-style: normal;font-weight: 400;text-align: justify;font-size: 16px;"> <section style="border-bottom: 1px solid black;margin: 0.5em 0px;line-height: 1.2;box-sizing: border-box;"> <section style="display: inline-block;border-color: rgb(89, 89, 89);border-bottom: 6px solid rgb(89, 89, 89);margin-bottom: -1px;font-size: 20px;color: rgb(89, 89, 89);box-sizing: border-box;"> <p style="margin: 0px;padding: 0px;box-sizing: border-box;">如何低成本的实现微服务？</p> </section> </section> </section> <section style="line-height: normal;"> <br> </section> <p style="text-align: justify;marg

<section style="white-space: normal;text-align: center;" data-mpa-powered-by="yiban.io"> <span style="font-size: 13px;color: rgb(136, 136, 136);font-family: Georgia, &quot;Times New Roman&quot;, Times, &quot;Songti SC&quot;, serif;letter-spacing: 0.544px;">点击上方蓝色“</span> <span style="font-size: 13px;font-family: Georgia, &quot;Times New Roman&quot;, Times, &quot;Songti SC&quot;, serif;letter-spacing: 0.544px;color: rgb(0, 128, 255);">程序猿DD</span> <span style="font-size: 13px;color: rgb(136, 136, 136);font-family: Georgia, &quot;Times New Roman&quot;, Times, &quot;Songti SC&quot;, serif;letter-spacing: 0.544px;">”，选择“设为星标”</span> <strong style="letter-spacing: 0.544px;color: rgb(74, 74, 74);font-family: Avenir, -apple-system-font, 微软雅黑, sans-serif;font-size: 16px;white-space: pre-line;background-color: rgb(255, 255, 255);text-align: right;"></strong> </section> <section style="white-space: normal;min-height: 1em;text-align: center;"> <span style="font-size: 13px;"><span style="color: rgb(136, 136, 136);font-family: Georgia, &quot;Times New Roman&quot;, Times, &quot;Songti SC&quot;, serif;letter-spacing: 0.544px;">回复“</span><span style="font-family: Georgia, &quot;Times New Roman&quot;, Times, &quot;Songti SC&quot;, serif;letter-spacing: 0.544px;color: rgb(0, 128, 255);">资源</span><span style="color: rgb(136, 136, 136);font-family: Georgia, &quot;Times New Roman&quot;, Times, &quot;Songti SC&quot;, serif;letter-spacing: 0.544px;">”获取独家整理的学习资料！</span></span> </section> <section style="margin-top: 10px;margin-bottom: 10px;white-space: normal;min-height: 1em;text-align: center;"> <span style="font-family: mp-quote, -apple-system-font, BlinkMacSystemFont, &quot;Helvetica Neue&quot;, &quot;PingFang SC&quot;, &quot;Hiragino Sans GB&quot;, &quot;Microsoft YaHei UI&quot;, &quot;Microsoft YaHei&quot;, Arial, sans-serif;"></span> <span style="color: rgb(136, 136, 136);font-family: Georgia, &quot;Times New Roman&quot;, Times, &quot;Songti SC&quot;, serif;font-size: 14px;letter-spacing: 0.544px;"><img data-backh="34" data-backw="540" data-ratio="0.0625" data-s="300,640" data-type="jpeg" data-w="640" width="100%" src="/upload/8c292e55ba5a23cb6ebc11f2a2c4fece.jpg" style="font-family: -apple-system-font, system-ui, &quot;Helvetica Neue&quot;, &quot;PingFang SC&quot;, &quot;Hiragino Sans GB&quot;, &quot;Microsoft YaHei UI&quot;, &quot;Microsoft YaHei&quot;, Arial, sans-serif;letter-spacing: 0.544px;box-sizing: border-box !important;visibility: visible !important;width: 654px !important;"></span> </section> <p style="text-align: center;"><img class="rich_pages" data-ratio="0.56171875" data-s="300,640" src="/upload/5c4e9af11d648601a1becb648a516612.jpg" data-type="jpeg" data-w="1280" style=""></p> <section style="white-space: normal;"> <span style="color: rgb(178, 178, 178);font-size: 13px;">来源：<span style="font-size: 13px;color: rgb(178, 178, 178);font-family: -apple-system-font, system-ui, &quot;Helvetica Neue&quot;, &quot;PingFang SC&quot;, &quot;Hiragino Sans GB&quot;, &quot;Microsoft YaHei UI&quot;, &quot;Microsoft YaHei&quot;, Arial, sans-serif;letter-spacing: 0.544px;text-align: left;background-color: rgb(255, 255, 255);">https://blog.csdn.net/vbirdbest/article/details/80207673</span></span> <br> </section> <section data-tool="mdnice编辑器" data-website="https://www.mdnice.com" style="font-family: -apple-system-font, system-ui, &quot;Helvetica Neue&quot;, &quot;PingFang SC&quot;, &quot;Hiragino Sans GB&quot;, &quot;Microsoft YaHei UI&quot;, &quot;Microsoft YaHei&quot;, Arial, sans-serif;letter-spacing: 0.544px;white-space: normal;background-color: rgb(255, 255, 255);"> <p style="margin: 1em 8px;font-size: inherit;line-height: 1.6 !important;"><span style="font-size: 15px;font-family: Optima-Regular, PingFangTC-light;"><strong style="font-family: mp-quote, -apple-system-font, BlinkMacSystemFont, &quot;Helvetica Neue&quot;, &quot;PingFang SC&quot;, &quot;Hiragino Sans GB&quot;, &quot;Microsoft YaHei UI&quot;, &quot;Microsoft YaHei&quot;, Arial, sans-serif;">一：简洁</strong><br></span></p> </section> <section data-tool="mdnice编辑器" data-website="https://www.mdnice.com" style="font-family: -apple-system-font, system-ui, &quot;Helvetica Neue&quot;, &quot;PingFang SC&quot;, &quot;Hiragino Sans GB&quot;, &quot;Microsoft YaHei UI&quot;, &quot;Microsoft YaHei&quot;, Arial, sans-serif;letter-spacing: 0.544px;white-space: normal;background-color: rgb(255, 255, 255);"> <section style="margin-bottom: 5px;padding-top: 8px;padding-bottom: 8px;line-height: 26px;color: rgb(89, 89, 89);"> <span style="font-size: 15px;font-family: Optima-Regular, PingFangTC-light;">方法引用分为三种，方法引用通过一对双冒号:: 来表示，方法引用是一种函数式接口的另一种书写方式</span> </section> <ul class="list-paddingleft-2"> <li><p style="margin-top: 5px;margin-bottom: 5px;padding-top: 8px;padding-bottom: 8px;color: rgb(89, 89, 89);line-height: normal;"><span style="font-family: Optima-Regular, PingFangTC-light;font-size: 15px;">静态方法引用，</span><span style="font-family: Optima-Regular, PingFangTC-light;font-size: 15px;">通过类名::静态方法名， 如 Integer::parseInt</span></p></li> <li><p style="margin-top: 5px;margin-bottom: 5px;padding-top: 8px;padding-bottom: 8px;color: rgb(89, 89, 89);line-height: normal;"><span style="font-family: Optima-Regular, PingFangTC-light;font-size: 15px;">实例方法引用，通过实例对象::实例方法，如 str::substring</span></p></li> <li><p style="margin-top: 5px;margin-bottom: 5px;padding-top: 8px;padding-bottom: 8px;color: rgb(89, 89, 89);line-height: normal;"><span style="font-family: Optima-Regular, PingFangTC-light;font-size: 15px;">构造方法引用，通过类名::new， 如 User::new</span></p></li> </ul> <h1 data-tool="mdnice编辑器" style="margin-top: 30px;margin-bottom: 15px;font-weight: bold;font-size: 24px;color: rgb(89, 89, 89);"><span style="font-size: 15px;font-family: Optima-Regular, PingFangTC-light;">二：方法引用</span></h1> <section data-mpa-preserve-tpl-color="t" data-mpa-template="t" mpa-preserve="t" mpa-from-tpl="t"> <pre style="background: none;"><code style="margin-right: 0.15em;margin-left: 0.15em;padding: 5.95px;border-radius: 4px;font-size: 0.85em;background: rgb(248, 248, 248);display

<p data-mpa-powered-by="yiban.io" style="max-width: 100%;min-height: 1em;letter-spacing: 0.544px;white-space: normal;background-color: rgb(255, 255, 255);color: rgb(62, 71, 83);font-family: &quot;Helvetica Neue&quot;, Helvetica, &quot;Hiragino Sans GB&quot;, &quot;Microsoft YaHei&quot;, Arial, sans-serif;font-size: 15px;text-align: center;box-sizing: border-box !important;overflow-wrap: break-word !important;"><span style="max-width: 100%;font-family: Optima-Regular, PingFangTC-light;box-sizing: border-box !important;overflow-wrap: break-word !important;"><span style="max-width: 100%;font-size: 16px;letter-spacing: 0.544px;box-sizing: border-box !important;overflow-wrap: break-word !important;"><span style="max-width: 100%;color: rgb(127, 127, 127);font-size: 14px;line-height: 1.75em;box-sizing: border-box !important;overflow-wrap: break-word !important;">点击上方“</span><span style="max-width: 100%;font-size: 14px;line-height: 1.75em;color: rgb(0, 176, 240);box-sizing: border-box !important;overflow-wrap: break-word !important;">服务端思维</span><span style="max-width: 100%;color: rgb(127, 127, 127);font-size: 14px;line-height: 1.75em;box-sizing: border-box !important;overflow-wrap: break-word !important;">”，选择“</span></span><span style="max-width: 100%;color: rgb(136, 136, 136);font-size: 14px;box-sizing: border-box !important;overflow-wrap: break-word !important;">设为星标</span><span style="max-width: 100%;color: rgb(127, 127, 127);letter-spacing: 0.544px;font-size: 14px;box-sizing: border-box !important;overflow-wrap: break-word !important;">”</span></span></p> <p style="max-width: 100%;min-height: 1em;letter-spacing: 0.544px;white-space: normal;background-color: rgb(255, 255, 255);font-family: &quot;Helvetica Neue&quot;, Helvetica, &quot;Hiragino Sans GB&quot;, &quot;Microsoft YaHei&quot;, Arial, sans-serif;color: rgb(62, 62, 62);font-size: 15px;text-align: center;box-sizing: border-box !important;overflow-wrap: break-word !important;"><span style="max-width: 100%;font-family: Optima-Regular, PingFangTC-light;box-sizing: border-box !important;overflow-wrap: break-word !important;"><span style="max-width: 100%;letter-spacing: 0.544px;color: rgb(127, 127, 127);font-size: 14px;box-sizing: border-box !important;overflow-wrap: break-word !important;">回复”</span><span style="max-width: 100%;letter-spacing: 0.544px;font-size: 14px;color: rgb(0, 122, 170);box-sizing: border-box !important;overflow-wrap: break-word !important;">669</span><span style="max-width: 100%;letter-spacing: 0.544px;color: rgb(127, 127, 127);font-size: 14px;box-sizing: border-box !important;overflow-wrap: break-word !important;">“获取独家整理的精选资料集</span></span></p> <p style="max-width: 100%;min-height: 1em;letter-spacing: 0.544px;white-space: normal;background-color: rgb(255, 255, 255);font-family: &quot;Helvetica Neue&quot;, Helvetica, &quot;Hiragino Sans GB&quot;, &quot;Microsoft YaHei&quot;, Arial, sans-serif;color: rgb(62, 62, 62);font-size: 15px;text-align: center;box-sizing: border-box !important;overflow-wrap: break-word !important;"><span style="max-width: 100%;font-family: Optima-Regular, PingFangTC-light;letter-spacing: 0.544px;color: rgb(127, 127, 127);font-size: 14px;box-sizing: border-box !important;overflow-wrap: break-word !important;"><span style="max-width: 100%;letter-spacing: 0.544px;box-sizing: border-box !important;overflow-wrap: break-word !important;">回复”</span><span style="max-width: 100%;letter-spacing: 0.544px;color: rgb(0, 122, 170);box-sizing: border-box !important;overflow-wrap: break-word !important;">加群</span><span style="max-width: 100%;letter-spacing: 0.544px;box-sizing: border-box !important;overflow-wrap: break-word !important;">“加入全国服务端高端社群「后端圈」</span></span></p> <p style="text-align: center;"><img class="rich_pages js_insertlocalimg" data-backh="325" data-backw="579" data-ratio="0.5625" data-s="300,640" src="/upload/f837fde7657edcd2080e32c9a589a074.jpg" data-type="jpeg" data-w="1280" style="width: 100%;height: auto;"></p> <header style="overflow: hidden;width: 690px;margin-right: auto;margin-left: auto;color: rgb(18, 18, 18);font-family: -apple-system, BlinkMacSystemFont, &quot;Helvetica Neue&quot;, &quot;PingFang SC&quot;, &quot;Microsoft YaHei&quot;, &quot;Source Han Sans SC&quot;, &quot;Noto Sans CJK SC&quot;, &quot;WenQuanYi Micro Hei&quot;, sans-serif;font-size: medium;text-align: start;white-space: normal;background-color: rgb(255, 255, 255);"> <p style="margin-bottom: 1.4em;color: rgb(18, 18, 18);font-family: -apple-system, BlinkMacSystemFont, &quot;Helvetica Neue&quot;, &quot;PingFang SC&quot;, &quot;Microsoft YaHei&quot;, &quot;Source Han Sans SC&quot;, &quot;Noto Sans CJK SC&quot;, &quot;WenQuanYi Micro Hei&quot;, sans-serif;font-size: medium;text-align: start;white-space: normal;background-color: rgb(255, 255, 255);"><span style="font-weight: 600;">Redis 数据库内存数据满了，会宕机吗？</span></p> <p style="margin-top: 1.4em;margin-bottom: 1.4em;color: rgb(18, 18, 18);font-family: -apple-system, BlinkMacSystemFont, &quot;Helvetica Neue&quot;, &quot;PingFang SC&quot;, &quot;Microsoft YaHei&quot;, &quot;Source Han Sans SC&quot;, &quot;Noto Sans CJK SC&quot;, &quot;WenQuanYi Micro Hei&quot;, sans-serif;font-size: medium;text-align: start;white-space: normal;background-color: rgb(255, 255, 255);">答案是：不会让它出现存满的情况，在使用Redis的时候我们要配置Redis能使用的最大的内存大小，存到一定容量的时候还有Redis的内存淘汰策略呢，还有LRU算法进行淘汰，等等。。。</p> <p style="margin-top: 1.4em;margin-bottom: 1.4em;color: rgb(18, 18, 18);font-family: -apple-system, BlinkMacSystemFont, &quot;Helvetica Neue&quot;, &quot;PingFang SC&quot;, &quot;Microsoft YaHei&quot;, &quot;Source Han Sans SC&quot;, &quot;Noto Sans CJK SC&quot;, &quot;WenQuanYi Micro Hei&quot;, sans-serif;font-size: medium;text-align: start;white-space: normal;background-color: rgb(255, 255, 255);">接下来一起探讨下，Redis的内存淘汰策略。<br></p> <h3 style="margin-top: 1.90909em;margin-bottom: 1.27273em;font-variant-numeric: inherit;font-weight: 600;font-stretch: inherit;font-size: 1.1em;line-height: 1.5;font-family: -apple-system, BlinkMacSystemFont, &quot;Helvetica Neue&quot;, &quot;PingFang SC&quot;, &quot;Microsoft YaHei&quot;, &quot;Source Han Sans SC&quot;, &quot;Noto Sans CJK SC&quot;, &quot;WenQuanYi Micro Hei&quot;, sans-serif;clear: left;color: rgb(18, 18, 18);text-align: start;white-space: normal;background-color: rgb(255, 255, 255);">Redis占用内存大小</h3> <p style="margin-top: 1.4em;margin-bottom: 1.4em;color: rgb(18, 18, 18);font-family: -apple-system, BlinkMacSystemFont, &quot;Helvetica Neue&quot;, &quot;PingFang SC&quot;, &quot;Microsoft YaHei&quot;, &quot;Source Han Sans SC&quot;, &quot;Noto Sans CJK SC&quot;, &quot;WenQuanYi Micro Hei&quot;, sans-serif;font-size: medium;text-align: start;white-space: normal;background-color: rgb(255, 255, 255);">我们知道Redis是基于内存的key-value数据库，因为系统的内存大小有限，所以我们在使用Redis的时候可以配置Redis能使用的最大的内存大小。</p> <h3 style="margin-top: 1.90909em;margin-bottom: 1.27273em;font-variant-numeric: inherit;font-weight: 600;font-stretch: inherit;font-size: 1.1em;line-height: 1.5;font-family: -apple-system, BlinkMacSystemFont, &quot;Helvetica Neue&quot;, &quot;PingFang SC&quot;, &quot;Microsoft YaHei&quot;, &quot;Source Han Sans SC&quot;, &quot;Noto Sans CJK SC&quot;, &quot;WenQuanYi Micro Hei&quot;, sans-serif;clear: left;color: rgb(18, 18, 18);text-align: start;white-space: normal;background-color: rgb(255, 255, 255);">1、通过配置文件配置</h3> <p style="margin-top: 1.4em;margin-bottom: 1.4em;color: rgb(18, 18, 18);font-family: -apple-system, BlinkMacSystemFont, &quot;Helvetica Neue&quot;, &quot;PingFang SC&quot;, &quot;Microsoft YaHei&quot;, &quot;Source Han Sans SC&quot;, &quot;Noto Sans CJK SC&quot;, &quot;WenQuanYi Micro Hei&quot;, sans-serif;font-size: medium;text-align: start;white-space: normal;background-color: rgb(255, 255, 255);">通过在Redis安装目录下面的redis.conf配置文件中添加以下配置设置内存大小</p> <pre style="padding: 0.88889em;font-size: 0.9em;word-break: normal;overflow-wrap: normal;overflow: auto;background: rgb(246, 246, 246);border-radius: 4px;"><code style="border-radius: 0px;font-family: Menlo, Monaco, Consolas, &quot;Andale Mono&quot;, &quot;lucida console&quot;, &quot;Courier New&quot;, monospace;font-size: inherit;background-color: inherit;">//设置Redis最大占用内存大小为100M<br>maxmemory 100mb</code></pre> <blockquote style="margin-top: 1.4em;margin-bottom: 1.4em;padding-left: 1em;color: rgb(100, 100, 100);border-left-color: rgb(211, 211, 211);font-family: -apple-system, BlinkMacSystemFont, &quot;Helvetica Neue&quot;, &quot;PingFang SC&quot;, &quot;Microsoft YaHei&quot;, &quot;Source Han Sans SC&quot;, &quot;Noto Sans CJK SC&quot;, &quot;WenQuanYi Micro Hei&quot;, sans-serif;font-size: medium;text-align: start;white-space: normal;background-color: rgb(255, 255, 255);"> redis的配置文件不一定使用的是安装目录下面的redis.conf文件，启动redis服务的时候是可以传一个参数指定redis的配置文件的 </blockquote> <h3 style="margin-top: 1.90909em;margin-bottom: 1.27273em;font-variant-numeric: inherit;font-weight: 600;font-stretch: inherit;font-size: 1.1em;line-height: 1.5;font-family: -apple-system, BlinkMacSystemFont, &quot;Helvetica Neue&quot;, &quot;PingFang SC&quot;, &quot;Microsoft YaHei&quot;, &quot;Source Han Sans SC&quot;, &quot;Noto Sans CJK SC&quot;, &quot;WenQuanYi Micro Hei&quot;, sans-serif;clear: left;color: rgb(18, 18, 18);text-align: start;white-space: normal;background-color: rgb(255, 255, 255);">2、通过命令修改</h3> <p style="margin-top: 1.4em;margin-bottom: 1.4em;color: rgb(18, 18, 18);font-family: -apple-system, BlinkMacSystemFont, &quot;Helvetica Neue&quot;, &quot;PingFang SC&quot;, &quot;Microsoft YaHei&quot;, &quot;Source Han Sans SC&quot;, &quot;Noto Sans CJK SC&quot;, &quot;WenQuanYi Micro Hei&quot;, sans-serif;font-size: medium;text-align: start;white-space: normal;background-color: rgb(255, 255, 255);">Redis支持运行时通过命令动态修改内存大小</p> <pre style="padding: 0.88889em;font-size: 0.9em;word-break: normal;overflow-wrap: normal;overflow: auto;background: rgb(246, 246, 246);border-radius: 4px;"><code style="border-radius: 0px;font-family: Menlo, Monaco, Consolas, &quot;Andale Mono&quot;, &quot;lucida console&quot;, &quot;Courier New&quot;, monospace;font-size: inherit;background-color: inherit;">//设置Redis最大占用内存大小为100M`<br><br>127.0.0.1:6379&gt; config set maxmemory 100mb`<br><br>//获取设置的Redis能使用的最大内存大小`<br><br>127.0.0.1:6379&gt; config get maxmemory`</code></pre> <p style="margin-top: -0.8em;margin-bottom: -0.8em;color: rgb(18, 18, 18);font-family: -apple-system, BlinkMacSystemFont, &quot;Helvetica Neue&quot;, &quot;PingFang SC&quot;, &quot;Microsoft YaHei&quot;, &quot;Source Han Sans SC&quot;, &quot;Noto Sans CJK SC&quot;, &quot;WenQuanYi Micro Hei&quot;, sans-serif;font-size: medium;text-align: start;white-space: normal;background-color: rgb(255, 255, 255);"><br></p> <blockquote style="margin-top: 1.4em;margin-bottom: 1.4em;padding-left: 1em;color: rgb(100, 100, 100);border-left-color: rgb(211, 211, 211);font-family: -apple-system, BlinkMacSystemFont, &quot;Helvetica Neue&quot;, &quot;PingFang SC&quot;, &quot;Microsoft YaHei&quot;, &quot;Source Han Sans SC&quot;, &quot;Noto Sans CJK SC&quot;, &quot;WenQuanYi Micro Hei&quot;, sans-serif;font-size: medium;text-align: start;white-space: normal;background-color: rgb(255, 255, 255);"> 如果不设置最大内存大小或者设置最大内存大小为0，在64位操作系统下不限制内存大小，在32位操作系统下最多使用3GB内存 </blockquote> <h3 style="margin-top: 1.90909em;margin-bottom: 1.27273em;font-variant-numeric: inherit;font-weight: 600;font-stretch: inherit;font-size: 1.1em;line-height: 1.5;font-family: -apple-system, BlinkMacSystemFont, &quot;Helvetica Neue&quot;, &quot;PingFang SC&quot;, &quot;Microsoft YaHei&quot;, &quot;Source Han Sans SC&quot;, &quot;Noto Sans CJK SC&quot;, &quot;WenQuanYi Micro Hei&quot;, sans-serif;clear: left;color: rgb(18, 18, 18);text-align: start;white-space: normal;background-color: rgb(255, 255, 255);">Redis的内存淘汰</h3> <p style="margin-top: 1.4em;margin-bottom: 1.4em;color: rgb(18, 18, 18);font-family: -apple-system, BlinkMacSystemFont, &quot;Helvetica Neue&quot;, &quot;PingFang SC&quot;, &quot;Microsoft YaHei&quot;, &quot;Source Han Sans SC&quot;, &quot;Noto Sans CJK SC&quot;, &quot;WenQuanYi Micro Hei&quot;, sans-serif;font-size: medium;text-align: start;white-space: normal;background-color: rgb(255, 255, 255);">既然可以设置Redis最大占用内存大小，那么配置的内存就有用完的时候。那在内存用完的时候，还继续往Redis里面添加数据不就没内存可用了吗？</p> <p style="margin-top: 1.4em;margin-bottom: 1.4em;color: rgb(18, 18, 18);font-family: -apple-system, BlinkMacSystemFont, &quot;Helvetica Neue&quot;, &quot;PingFang SC&quot;, &quot;Microsoft YaHei&quot;, &quot;Source Han Sans SC&quot;, &quot;Noto Sans CJK SC&quot;, &quot;WenQuanYi Micro Hei&quot;, sans-serif;font-size: medium;text-align: start;white-space: normal;background-color: rgb(255, 255, 255);">实际上Redis定义了几种策略用来处理这种情况：</p> <p style="margin-top: 1.4em;margin-bottom: 1.4em;color: rgb(18, 18, 18);font-family: -apple-system, BlinkMacSystemFont, &quot;Helvetica Neue&quot;, &quot;PingFang SC&quot;, &quot;Microsoft YaHei&quot;, &quot;Source Han Sans SC&quot;, &quot;Noto Sans CJK SC&quot;, &quot;WenQuanYi Micro Hei&quot;, sans-serif;font-size: medium;text-align: start;white-space: normal;background-color: rgb(255, 255, 255);"><span style="font-weight: 600;">noeviction(默认策略)</span>：对于写请求不再提供服务，直接返回错误（DEL请求和部分特殊请求除外）</p> <p style="margin-top: 1.4em;margin-bottom: 1.4em;color: rgb(18, 18, 18);font-family: -apple-system, BlinkMacSystemFont, &quot;Helvetica Neue&quot;, &quot;PingFang SC&quot;, &quot;Microsoft YaHei&quot;, &quot;Source Han Sans SC&quot;, &quot;Noto Sans CJK SC&quot;, &quot;WenQuanYi Micro Hei&quot;, sans-serif;font-size: medium;text-align: start;white-space: normal;background-color: rgb(255, 255, 255);"><span style="font-weight: 600;">allkeys-lru</span>：从所有key中使用LRU算法进行淘汰</p> <p style="margin-top: 1.4em;margin-bottom: 1.4em;color: rgb(18, 18, 18);font-family: -apple-system, BlinkMacSystemFont, &quot;Helvetica Neue&quot;, &quot;PingFang SC&quot;, &quot;Microsoft YaHei&quot;, &quot;Source Han Sans SC&quot;, &quot;Noto Sans CJK SC&quot;, &quot;WenQuanYi Micro Hei&quot;, sans-serif;font-size: medium;text-align: start;white-space: normal;background-color: rgb(255, 255, 255);"><span style="font-weight: 600;">volatile-lru</span>：从设置了过期时间的key中使用LRU算法进行淘汰</p> <p style="margin-top: 1.4em;margin-bottom: 1.4em;color: rgb(18, 18, 18);font-family: -apple-system, BlinkMacSystemFont, &quot;Helvetica Neue&quot;, &quot;PingFang SC&quot;, &quot;Microsoft YaHei&quot;, &quot;Source Han Sans SC&quot;, &quot;Noto Sans CJK SC&quot;, &quot;WenQuanYi Micro Hei&quot;, sans-serif;font-size: medium;text-align: start;white-space: normal;background-color: rgb(255, 255, 255);"><span style="font-weight: 600;">allkeys-random</span>：从所有key中随机淘汰数据</p> <p style="margin-top: 1.4em;margin-bottom: 1.4em;color: rgb(18, 18, 18);font-family: -apple-system, BlinkMacSystemFont, &quot;Helvetica Neue&quot;, &quot;PingFang SC&quot;, &quot;Microsoft YaHei&quot;, &quot;Source Han Sans SC&quot;, &quot;Noto Sans CJK SC&quot;, &quot;WenQuanYi Micro Hei&quot;, sans-serif;font-size: medium;text-align: start;white-space: normal;background-color: rgb(255, 255, 255);"><span style="font-weight: 600;">volatile-random</span>：从设置了过期时间的key中随机淘汰</p> <p style="margin-top: 1.4em;margin-bottom: 1.4em;color: rgb(18, 18, 18);font-family: -apple-system, BlinkMacSystemFont, &quot;Helvetica Neue&quot;, &quot;PingFang SC&quot;, &quot;Microsoft YaHei&quot;, &quot;Source Han Sans SC&quot;, &quot;Noto Sans CJK SC&quot;, &quot;WenQuanYi Micro Hei&quot;, sans-serif;font-size: medium;text-align: start;white-space: normal;background-color: rgb(255, 255, 255);"><span style="font-weight: 600;">volatile-ttl</span>：在设置了过期时间的key中，根据key的过期时间进行淘汰，越早过期的越优先被淘汰</p> <blockquote style="margin-top: 1.4em;margin-bottom: 1.4em;padding-left: 1em;color: rgb(100, 100, 100);border-left-color: rgb(211, 211, 211);font-family: -apple-system, BlinkMacSystemFont, &quot;Helvetica Neue&quot;, &quot;PingFang SC&quot;, &quot;Microsoft YaHei&quot;, &quot;Source Han Sans SC&quot;, &quot;Noto Sans CJK SC&quot;, &quot;WenQuanYi Micro Hei&quot;, sans-serif;font-size: medium;text-align: start;white-space: normal;background-color: rgb(255, 255, 255);"> 当使用 <span style="font-weight: 600;">volatile-lru</span>、 <span style="font-weight: 600;">volatile-random</span>、 <span style="font-weight: 600;">volatile-ttl</span>这三种策略时，如果没有key可以被淘汰，则和 <span style="font-weight: 600;">noeviction</span>一样返回错误 </blockquote> <h3 style="margin-top: 1.90909em;margin-bottom: 1.27273em;font-variant-numeric: inherit;font-weight: 600;font-stretch: inherit;font-size: 1.1em;line-height: 1.5;font-family: -apple-system, BlinkMacSystemFont, &quot;Helvetica Neue&quot;, &quot;PingFang SC&quot;, &quot;Microsoft YaHei&quot;, &quot;Source Han Sans SC&quot;, &quot;Noto Sans CJK SC&quot;, &quot;WenQuanYi Micro Hei&quot;, sans-serif;clear: left;color: rgb(18, 18, 18);text-align: start;white-space: normal;background-color: rgb(255, 255, 255);">如何获取及设置内存淘汰策略</h3> <p style="margin-top: 1.4em;margin-bottom: 1.4em;color: rgb(18, 18, 18);font-family: -apple-system, BlinkMacSystemFont, &quot;Helvetica Neue&quot;, &quot;PingFang SC&quot;, &quot;Microsoft YaHei&quot;, &quot;Source Han Sans SC&quot;, &quot;Noto Sans CJK SC&quot;, &quot;WenQuanYi Micro Hei&quot;, sans-serif;font-size: medium;text-align: start;white-space: normal;background-color: rgb(255, 255, 255);">获取当前内存淘汰策略：</p> <pre style="padding: 0.88889em;font-size: 0.9em;word-break: normal;overflow-wrap: normal;overflow: auto;background: rgb(246, 246, 246);border-radius: 4px;"><code style="border-radius: 0px;font-family: Menlo, Monaco, Consolas, &quot;Andale Mono&quot;, &quot;lucida console&quot;, &quot;Courier New&quot;, monospace;font-size: inherit;background-color: inherit;">127.0.0.1:6379&gt; config get maxmemory-policy</code></pre> <p style="margin-top: -0.8em;margin-bottom: -0.8em;color: rgb(18, 18, 18);font-family: -apple-system, BlinkMacSystemFont, &quot;Helvetica Neue&quot;, &quot;PingFang SC&quot;, &quot;Microsoft YaHei&quot;, &quot;Source Han Sans SC&quot;, &quot;Noto Sans CJK SC&quot;, &quot;WenQuanYi Micro Hei&quot;, sans-serif;font-size: medium;text-align: start;white-space: normal;background-color: rgb(255, 255, 255);"><br></p> <p style="margin-top: 1.4em;margin-bottom: 1.4em;color: rgb(18, 18, 18);font-family: -apple-system, BlinkMacSystemFont, &quot;Helvetica Neue&quot;, &quot;PingFang SC&quot;, &quot;Microsoft YaHei&quot;, &quot;Source Han Sans SC&quot;, &quot;Noto Sans CJK SC&quot;, &quot;WenQuanYi Micro Hei&quot;, sans-serif;font-size: medium;text-align: start;white-space: normal;background-color: rgb(255, 255, 255);">通过配置文件设置淘汰策略（修改redis.conf文件）：</p> <pre style="padding: 0.88889em;font-size: 0.9em;word-break: normal;overflow-wrap: normal;overflow: auto;background: rgb(246, 246, 246);border-radius: 4px;"><code style="border-radius: 0px;font-family: Menlo, Monaco, Consolas, &quot;Andale Mono&quot;, &quot;lucida console&quot;, &quot;Courier New&quot;, monospace;font-size: inherit;background-color: inherit;">maxmemory-policy allkeys-lru</code></pre> <p style="margin-top: 1.4em;margin-bottom: 1.4em;color: rgb(18, 18, 18);font-family: -apple-system, BlinkMacSystemFont, &quot;Helvetica Neue&quot;, &quot;PingFang SC&quot;, &quot;Microsoft YaHei&quot;, &quot;Source Han Sans SC&quot;, &quot;Noto Sans CJK SC&quot;, &quot;WenQuanYi Micro Hei&quot;, sans-serif;font-size: medium;text-align: start;white-space: normal;background-color: rgb(255, 255, 255);">通过命令修改淘汰策略：</p> <pre style="padding: 0.88889em;font-size: 0.9em;word-break: normal;overflow-wrap: normal;overflow: auto;background: rgb(246, 246, 246);border-radius: 4px;"><code style="border-radius: 0px;font-family: Menlo, Monaco, Consolas, &quot;Andale Mono&quot;, &quot;lucida console&quot;, &quot;Courier New&quot;, monospace;font-size: inherit;background-color: inherit;">127.0.0.1:6379&gt; config set maxmemory-policy allkeys-lru`</code></pre> <h3 style="margin-top: 1.90909em;margin-bottom: 1.27273em;font-variant-numeric: inherit;font-weight: 600;font-stretch: inherit;font-size: 1.1em;line-height: 1.5;font-family: -apple-system, BlinkMacSystemFont, &quot;Helvetica Neue&quot;, &quot;PingFang SC&quot;, &quot;Microsoft YaHei&quot;, &quot;Source Han Sans SC&quot;, &quot;Noto Sans CJK SC&quot;, &quot;WenQuanYi Micro Hei&quot;, sans-serif;clear: left;color: rgb(18, 18, 18);text-align: start;white-space: normal;background-color: rgb(255, 255, 255);">LRU算法</h3> <h3 style="margin-top: 1.90909em;margin-bottom: 1.27273em;font-variant-numeric: inherit;font-weight: 600;font-stretch: inherit;font-size: 1.1em;line-height: 1.5;font-family: -apple-system, BlinkMacSystemFont, &quot;Helvetica Neue&quot;, &quot;PingFang SC&quot;, &quot;Microsoft YaHei&quot;, &quot;Source Han Sans SC&quot;, &quot;Noto Sans CJK SC&quot;, &quot;WenQuanYi Micro Hei&quot;, sans-serif;clear: left;color: rgb(18, 18, 18);text-align: start;white-space: normal;background-color: rgb(255, 255, 255);">什么是LRU?</h3> <p style="margin-top: 1.4em;margin-bottom: 1.4em;color: rgb(18, 18, 18);font-family: -apple-system, BlinkMacSystemFont, &quot;Helvetica Neue&quot;, &quot;PingFang SC&quot;, &quot;Microsoft YaHei&quot;, &quot;Source Han Sans SC&quot;, &quot;Noto Sans CJK SC&quot;, &quot;WenQuanYi Micro Hei&quot;, sans-serif;font-size: medium;text-align: start;white-space: normal;background-color: rgb(255, 255, 255);">上面说到了Redis可使用最大内存使用完了，是可以使用LRU算法进行内存淘汰的，那么什么是LRU算法呢？</p> <blockquote style="margin-top: 1.4em;margin-bottom: 1.4em;padding-left: 1em;color: rgb(100, 100, 100);border-left-color: rgb(211, 211, 211);font-family: -apple-system, BlinkMacSystemFont, &quot;Helvetica Neue&quot;, &quot;PingFang SC&quot;, &quot;Microsoft YaHei&quot;, &quot;Source Han Sans SC&quot;, &quot;Noto Sans CJK SC&quot;, &quot;WenQuanYi Micro Hei&quot;, sans-serif;font-size: medium;text-align: start;white-space: normal;background-color: rgb(255, 255, 255);"> <span style="font-weight: 600;">LRU(Least Recently Used)</span>，即最近最少使用，是一种缓存置换算法。在使用内存作为缓存的时候，缓存的大小一般是固定的。当缓存被占满，这个时候继续往缓存里面添加数据，就需要淘汰一部分老的数据，释放内存空间用来存储新的数据。这个时候就可以使用LRU算法了。其核心思想是：如果一个数据在最近一段时间没有被用到，那么将来被使用到的可能性也很小，所以就可以被淘汰掉。 </blockquote> <h3 style="margin-top: 1.90909em;margin-bottom: 1.27273em;font-variant-numeric: inherit;font-weight: 600;font-stretch: inherit;font-size: 1.1em;line-height: 1.5;font-family: -apple-system, BlinkMacSystemFont, &quot;Helvetica Neue&quot;, &quot;PingFang SC&quot;, &quot;Microsoft YaHei&quot;, &quot;Source Han Sans SC&quot;, &quot;Noto Sans CJK SC&quot;, &quot;WenQuanYi Micro Hei&quot;, sans-serif;clear: left;color: rgb(18, 18, 18);text-align: start;white-space: normal;background-color: rgb(255, 255, 255);">LRU在Redis中的实现</h3> <h3 style="margin-top: 1.90909em;margin-bottom: 1.27273em;font-variant-numeric: inherit;font-weight: 600;font-stretch: inherit;font-size: 1.1em;line-height: 1.5;font-family: -apple-system, BlinkMacSystemFont, &quot;Helvetica Neue&quot;, &quot;PingFang SC&quot;, &quot;Microsoft YaHei&quot;, &quot;Source Han Sans SC&quot;, &quot;Noto Sans CJK SC&quot;, &quot;WenQuanYi Micro Hei&quot;, sans-serif;clear: left;color: rgb(18, 18, 18);text-align: start;white-space: normal;background-color: rgb(255, 255, 255);">近似LRU算法</h3> <p style="margin-top: 1.4em;margin-bottom: 1.4em;color: rgb(18, 18, 18);font-family: -apple-system, BlinkMacSystemFont, &quot;Helvetica Neue&quot;, &quot;PingFang SC&quot;, &quot;Microsoft YaHei&quot;, &quot;Source Han Sans SC&quot;, &quot;Noto Sans CJK SC&quot;, &quot;WenQuanYi Micro Hei&quot;, sans-serif;font-size: medium;text-align: start;white-space: normal;background-color: rgb(255, 255, 255);">Redis使用的是近似LRU算法，它跟常规的LRU算法还不太一样。近似LRU算法通过随机采样法淘汰数据，每次随机出5（默认）个key，从里面淘汰掉最近最少使用的key。</p> <blockquote style="margin-top: 1.4em;margin-bottom: 1.4em;padding-left: 1em;color: rgb(100, 100, 100);border-left-color: rgb(211, 211, 211);font-family: -apple-system, BlinkMacSystemFont, &quot;Helvetica Neue&quot;, &quot;PingFang SC&quot;, &quot;Microsoft YaHei&quot;, &quot;Source Han Sans SC&quot;, &quot;Noto Sans CJK SC&quot;, &quot;WenQuanYi Micro Hei&quot;, sans-serif;font-size: medium;text-align: start;white-space: normal;background-color: rgb(255, 255, 255);"> 可以通过maxmemory-samples参数修改采样数量：例：maxmemory-samples 10 maxmenory-samples配置的越大，淘汰的结果越接近于严格的LRU算法 </blockquote> <p style="margin-top: 1.4em;margin-bottom: 1.4em;color: rgb(18, 18, 18);font-family: -apple-system, BlinkMacSystemFont, &quot;Helvetica Neue&quot;, &quot;PingFang SC&quot;, &quot;Microsoft YaHei&quot;, &quot;Source Han Sans SC&quot;, &quot;Noto Sans CJK SC&quot;, &quot;WenQuanYi Micro Hei&quot;, sans-serif;font-size: medium;text-align: start;white-space: normal;background-color: rgb(255, 255, 255);">Redis为了实现近似LRU算法，给每个key增加了一个额外增加了一个24bit的字段，用来存储该key最后一次被访问的时间。</p> <h3 style="margin-top: 1.90909em;margin-bottom: 1.27273em;font-variant-numeric: inherit;font-weight: 600;font-stretch: inherit;font-size: 1.1em;line-height: 1.5;font-family: -apple-system, BlinkMacSystemFont, &quot;Helvetica Neue&quot;, &quot;PingFang SC&quot;, &quot;Microsoft YaHei&quot;, &quot;Source Han Sans SC&quot;, &quot;Noto Sans CJK SC&quot;, &quot;WenQuanYi Micro Hei&quot;, sans-serif;clear: left;color: rgb(18, 18, 18);text-align: start;white-space: normal;background-color: rgb(255, 255, 255);">Redis3.0对近似LRU的优化</h3> <p style="margin-top: 1.4em;margin-bottom: 1.4em;color: rgb(18, 18, 18);font-family: -apple-system, BlinkMacSystemFont, &quot;Helvetica Neue&quot;, &quot;PingFang SC&quot;, &quot;Microsoft YaHei&quot;, &quot;Source Han Sans SC&quot;, &quot;Noto Sans CJK SC&quot;, &quot;WenQuanYi Micro Hei&quot;, sans-serif;font-size: medium;text-align: start;white-space: normal;background-color: rgb(255, 255, 255);">Redis3.0对近似LRU算法进行了一些优化。新算法会维护一个候选池（大小为16），池中的数据根据访问时间进行排序，第一次随机选取的key都会放入池中，随后每次随机选取的key只有在访问时间小于池中最小的时间才会放入池中，直到候选池被放满。当放满后，如果有新的key需要放入，则将池中最后访问时间最大（最近被访问）的移除。</p> <p style="margin-top: 1.4em;margin-bottom: 1.4em;color: rgb(18, 18, 18);font-family: -apple-system, BlinkMacSystemFont, &quot;Helvetica Neue&quot;, &quot;PingFang SC&quot;, &quot;Microsoft YaHei&quot;, &quot;Source Han Sans SC&quot;, &quot;Noto Sans CJK SC&quot;, &quot;WenQuanYi Micro Hei&quot;, sans-serif;font-size: medium;text-align: start;white-space: normal;background-color: rgb(255, 255, 255);">当需要淘汰的时候，则直接从池中选取最近访问时间最小（最久没被访问）的key淘汰掉就行。</p> <h3 style="margin-top: 1.90909em;margin-bottom: 1.27273em;font-variant-numeric: inherit;font-weight: 600;font-stretch: inherit;font-size: 1.1em;line-height: 1.5;font-family: -apple-system, BlinkMacSystemFont, &quot;Helvetica Neue&quot;, &quot;PingFang SC&quot;, &quot;Microsoft YaHei&quot;, &quot;Source Han Sans SC&quot;, &quot;Noto Sans CJK SC&quot;, &quot;WenQuanYi Micro Hei&quot;, sans-serif;clear: left;color: rgb(18, 18, 18);text-align: start;white-space: normal;background-color: rgb(255, 255, 255);">LRU算法的对比</h3> <p style="margin-top: 1.4em;margin-bottom: 1.4em;color: rgb(18, 18, 18);font-family: -apple-system, BlinkMacSystemFont, &quot;Helvetica Neue&quot;, &quot;PingFang SC&quot;, &quot;Microsoft YaHei&quot;, &quot;Source Han Sans SC&quot;, &quot;Noto Sans CJK SC&quot;, &quot;WenQuanYi Micro Hei&quot;, sans-serif;font-size: medium;text-align: start;white-space: normal;background-color: rgb(255, 255, 255);">我们可以通过一个实验对比各LRU算法的准确率，先往Redis里面添加一定数量的数据n，使Redis可用内存用完，再往Redis里面添加n/2的新数据，这个时候就需要淘汰掉一部分的数据，如果按照严格的LRU算法，应该淘汰掉的是最先加入的n/2的数据。生成如下各LRU算法的对比图</p> <figure data-size="normal" style="margin-top: 1.4em;margin-bottom: 1.4em;color: rgb(18, 18, 18);font-family: -apple-system, BlinkMacSystemFont, &quot;Helvetica Neue&quot;, &quot;PingFang SC&quot;, &quot;Microsoft YaHei&quot;, &quot;Source Han Sans SC&quot;, &quot;Noto Sans CJK SC&quot;, &quot;WenQuanYi Micro Hei&quot;, sans-serif;font-size: medium;text-align: start;white-space: normal;background-color: rgb(255, 255, 255);"> <img src="/upload/c552afb8334c63345a7b08dab51f8dbd.jpg" data-cropx1="0" data-cropx2="720" data-cropy1="0" data-cropy2="310.506512301013" data-ratio="0.4305555555555556" src="https://mmbiz.qpic.cn/mmbiz_jpg/hUzEz6BmcaqicHb61lpHuh94EekcAowzGBia8pOjHFicwnWNCdSbceJ5cMacsWibNBOgEY4jxoc1LHUK7H00XwT4DQ/640?wx_fmt=jpeg" data-type="jpeg" data-w="720" style="display: block;margin-right: auto;margin-left: auto;cursor: zoom-in;background-color: transparent;animation: 0.5s ease-in 0s 1 normal none running fxRichTextFadeIn;width: 578px;height: 249px;"> </figure> <p style="margin-top: -0.8em;margin-bottom: -0.8em;color: rgb(18, 18, 18);font-family: -apple-system, BlinkMacSystemFont, &quot;Helvetica Neue&quot;, &quot;PingFang SC&quot;, &quot;Microsoft YaHei&quot;, &quot;Source Han Sans SC&quot;, &quot;Noto Sans CJK SC&quot;, &quot;WenQuanYi Micro Hei&quot;, sans-serif;font-size: medium;text-align: start;white-space: normal;background-color: rgb(255, 255, 255);"><br></p> <p style="margin-top: 1.4em;margin-bottom: 1.4em;color: rgb(18, 18, 18);font-family: -apple-system, BlinkMacSystemFont, &quot;Helvetica Neue&quot;, &quot;PingFang SC&quot;, &quot;Microsoft YaHei&quot;, &quot;Source Han Sans SC&quot;, &quot;Noto Sans CJK SC&quot;, &quot;WenQuanYi Micro Hei&quot;, sans-serif;font-size: medium;text-align: start;white-space: normal;background-color: rgb(255, 255, 255);">你可以看到图中有三种不同颜色的点：</p> <ul style="margin-top: 1.4em;margin-bottom: 1.4em;display: table;color: rgb(18, 18, 18);font-family: -apple-system, BlinkMacSystemFont, &quot;Helvetica Neue&quot;, &quot;PingFang SC&quot;, &quot;Microsoft YaHei&quot;, &quot;Source Han Sans SC&quot;, &quot;Noto Sans CJK SC&quot;, &quot;WenQuanYi Micro Hei&quot;, sans-serif;font-size: medium;text-align: start;white-space: normal;background-color: rgb(255, 255, 255);" class="list-paddingleft-2"> <li style="list-style: none;display: table-row;"><p>浅灰色是被淘汰的数据</p></li> <li style="list-style: none;display: table-row;"><p>灰色是没有被淘汰掉的老数据</p></li> <li style="list-style: none;display: table-row;"><p>绿色是新加入的数据</p></li> </ul> <p style="margin-top: 1.4em;margin-bottom: 1.4em;color: rgb(18, 18, 18);font-family: -apple-system, BlinkMacSystemFont, &quot;Helvetica Neue&quot;, &quot;PingFang SC&quot;, &quot;Microsoft YaHei&quot;, &quot;Source Han Sans SC&quot;, &quot;Noto Sans CJK SC&quot;, &quot;WenQuanYi Micro Hei&quot;, sans-serif;font-size: medium;text-align: start;white-space: normal;background-color: rgb(255, 255, 255);">我们能看到Redis3.0采样数是10生成的图最接近于严格的LRU。而同样使用5个采样数，Redis3.0也要优于Redis2.8。</p> <h3 style="margin-top: 1.90909em;margin-bottom: 1.27273em;font-variant-numeric: inherit;font-weight: 600;font-stretch: inherit;font-size: 1.1em;line-height: 1.5;font-family: -apple-system, BlinkMacSystemFont, &quot;Helvetica Neue&quot;, &quot;PingFang SC&quot;, &quot;Microsoft YaHei&quot;, &quot;Source Han Sans SC&quot;, &quot;Noto Sans CJK SC&quot;, &quot;WenQuanYi Micro Hei&quot;, sans-serif;clear: left;color: rgb(18, 18, 18);text-align: start;white-space: normal;background-color: rgb(255, 255, 255);">LFU算法</h3> <p style="margin-top: 1.4em;margin-bottom: 1.4em;color: rgb(18, 18, 18);font-family: -apple-system, BlinkMacSystemFont, &quot;Helvetica Neue&quot;, &quot;PingFang SC&quot;, &quot;Microsoft YaHei&quot;, &quot;Source Han Sans SC&quot;, &quot;Noto Sans CJK SC&quot;, &quot;WenQuanYi Micro Hei&quot;, sans-serif;font-size: medium;text-align: start;white-space: normal;background-color: rgb(255, 255, 255);">LFU算法是Redis4.0里面新加的一种淘汰策略。它的全称是<span style="font-weight: 600;">Least Frequently Used</span>，它的核心思想是根据key的最近被访问的频率进行淘汰，很少被访问的优先被淘汰，被访问的多的则被留下来。</p> <p style="margin-top: 1.4em;margin-bottom: 1.4em;color: rgb(18, 18, 18);font-family: -apple-system, BlinkMacSystemFont, &quot;Helvetica Neue&quot;, &quot;PingFang SC&quot;, &quot;Microsoft YaHei&quot;, &quot;Source Han Sans SC&quot;, &quot;Noto Sans CJK SC&quot;, &quot;WenQuanYi Micro Hei&quot;, sans-serif;font-size: medium;text-align: start;white-space: normal;background-color: rgb(255, 255, 255);">LFU算法能更好的表示一个key被访问的热度。假如你使用的是LRU算法，一个key很久没有被访问到，只刚刚是偶尔被访问了一次，那么它就被认为是热点数据，不会被淘汰，而有些key将来是很有可能被访问到的则被淘汰了。如果使用LFU算法则不会出现这种情况，因为使用一次并不会使一个key成为热点数据。</p> <p style="margin-top: 1.4em;margin-bottom: 1.4em;color: rgb(18, 18, 18);font-family: -apple-system, BlinkMacSystemFont, &quot;Helvetica Neue&quot;, &quot;PingFang SC&quot;, &quot;Microsoft YaHei&quot;, &quot;Source Han Sans SC&quot;, &quot;Noto Sans CJK SC&quot;, &quot;WenQuanYi Micro Hei&quot;, sans-serif;font-size: medium;text-align: start;white-space: normal;background-color: rgb(255, 255, 255);">LFU一共有两种策略：</p> <p style="margin-top: 1.4em;margin-bottom: 1.4em;color: rgb(18, 18, 18);font-family: -apple-system, BlinkMacSystemFont, &quot;Helvetica Neue&quot;, &quot;PingFang SC&quot;, &quot;Microsoft YaHei&quot;, &quot;Source Han Sans SC&quot;, &quot;Noto Sans CJK SC&quot;, &quot;WenQuanYi Micro Hei&quot;, sans-serif;font-size: medium;text-align: start;white-space: normal;background-color: rgb(255, 255, 255);">volatile-lfu：在设置了过期时间的key中使用LFU算法淘汰key</p> <p style="margin-top: 1.4em;margin-bottom: 1.4em;color: rgb(18, 18, 18);font-family: -apple-system, BlinkMacSystemFont, &quot;Helvetica Neue&quot;, &quot;PingFang SC&quot;, &quot;Microsoft YaHei&quot;, &quot;Source Han Sans SC&quot;, &quot;Noto Sans CJK SC&quot;, &quot;WenQuanYi Micro Hei&quot;, sans-serif;font-size: medium;text-align: start;white-space: normal;background-color: rgb(255, 255, 255);">allkeys-lfu：在所有的key中使用LFU算法淘汰数据</p> <blockquote style="margin-top: 1.4em;margin-bottom: 1.4em;padding-left: 1em;color: rgb(100, 100, 100);border-left-color: rgb(211, 211, 211);font-family: -apple-system, BlinkMacSystemFont, &quot;Helvetica Neue&quot;, &quot;PingFang SC&quot;, &quot;Microsoft YaHei&quot;, &quot;Source Han Sans SC&quot;, &quot;Noto Sans CJK SC&quot;, &quot;WenQuanYi Micro Hei&quot;, sans-serif;font-size: medium;text-align: start;white-space: normal;background-color: rgb(255, 255, 255);"> 设置使用这两种淘汰策略跟前面讲的一样，不过要注意的一点是这两周策略只能在Redis4.0及以上设置，如果在Redis4.0以下设置会报错 </blockquote> <h3 style="margin-top: 1.90909em;margin-bottom: 1.27273em;font-variant-numeric: inherit;font-weight: 600;font-stretch: inherit;font-size: 1.1em;line-height: 1.5;font-family: -apple-system, BlinkMacSystemFont, &quot;Helvetica Neue&quot;, &quot;PingFang SC&quot;, &quot;Microsoft YaHei&quot;, &quot;Source Han Sans SC&quot;, &quot;Noto Sans CJK SC&quot;, &quot;WenQuanYi Micro Hei&quot;, sans-serif;clear: left;color: rgb(18, 18, 18);text-align: start;white-space: normal;background-color: rgb(255, 255, 255);">问题</h3> <p style="margin-top: 1.4em;color: rgb(18, 18, 18);font-family: -apple-system, BlinkMacSystemFont, &quot;Helvetica Neue&quot;, &quot;PingFang SC&quot;, &quot;Microsoft YaHei&quot;, &quot;Source Han Sans SC&quot;, &quot;Noto Sans CJK SC&quot;, &quot;WenQuanYi Micro Hei&quot;, sans-serif;font-size: medium;text-align: start;white-space: normal;background-color: rgb(255, 255, 255);">最后留一个小问题，可能有的人注意到了，文中并没有解释为什么Redis使用近似LRU算法而不使用准确的LRU算法，可以一起讨论学习。</p> </header> <section powered-by="xiumi.us" style="max-width: 100%;font-size: 16px;letter-spacing: 0.544px;white-space: normal;background-color: rgb(255, 255, 255);text-align: center;color: rgb(62, 71, 83);font-family: &quot;Helvetica Neue&quot;, Helvetica, &quot;Hiragino Sans GB&quot;, &quot;Microsoft YaHei&quot;, Arial, sans-serif;box-sizing: border-box !important;overflow-wrap: break-word !important;"> <section style="max-width: 100%;box-sizing: border-box !important;overflow-wrap: break-word !important;"> <section style="max-width: 100%;box-sizing: border-box !important;overflow-wrap: break-word !important;"> <section style="max-width: 100%;box-sizing: border-box !important;overflow-wrap: break-word !important;"> <section powered-by="xiumi.us" style="max-width: 100%;box-sizing: border-box !important;overflow-wrap: break-word !important;"> <section style="max-width: 100%;box-sizing: border-box !important;overflow-wrap: break-word !important;"> <p style="margin-right: 16px;margin-left: 16px;max-width: 100%;min-height: 1em;letter-spacing: 1.5px;line-height: 1.5em;font-family: -apple-system-font, BlinkMacSystemFont, Arial, sans-serif;box-sizing: border-box !important;overflow-wrap: break-word !important;"><span style="max-width: 100%;color: rgb(77, 168, 238);box-sizing: border-box !important;overflow-wrap: break-word !important;"><strong style="max-width: 100%;box-sizing: border-box !important;overflow-wrap: break-word !important;"><span style="max-width: 100%;font-size: 12px;letter-spacing: 1px;box-sizing: border-box !important;overflow-wrap: break-word !important;"><strong style="max-width: 100%;font-size: 17px;letter-spacing: 0.544px;font-family: -apple-system-font, BlinkMacSystemFont, &quot;Helvetica Neue&quot;, &quot;PingFang SC&quot;, &quot;Hiragino Sans GB&quot;, &quot;Microsoft YaHei UI&quot;, &quot;Microsoft YaHei&quot;, Arial, sans-serif;box-sizing: border-box 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!important;"><br style="max-width: 100%;box-sizing: border-box !important;overflow-wrap: break-word !important;"></p> <p style="margin-right: 16px;margin-left: 16px;max-width: 100%;min-height: 1em;letter-spacing: 1.5px;line-height: 1.5em;font-family: -apple-system-font, BlinkMacSystemFont, Arial, sans-serif;box-sizing: border-box !important;overflow-wrap: break-word !important;"><strong style="max-width: 100%;box-sizing: border-box !important;overflow-wrap: break-word !important;"><span style="max-width: 100%;font-size: 12px;letter-spacing: 1px;color: rgb(0, 0, 0);box-sizing: border-box !important;overflow-wrap: break-word !important;">对「服务端思维」有期待，请在文末点个<span style="max-width: 100%;color: rgb(198, 19, 25);box-sizing: border-box !important;overflow-wrap: break-word !important;">在看</span></span></strong></p> <p style="margin-right: 16px;margin-left: 16px;max-width: 100%;min-height: 1em;letter-spacing: 1.5px;line-height: 1.5em;font-family: -apple-system-font, BlinkMacSystemFont, Arial, 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data-ratio="1" data-type="gif" data-w="100" data-width="100%" src="/upload/8b34c0e8ddcf33f56770ae9f44c95ce1.png" style="display: block;box-sizing: border-box !important;overflow-wrap: break-word !important;visibility: visible !important;width: 22px !important;"> </section> </section> </section> </section> </section> </section>

<p style="text-align: center;"><span style="font-size: 14px;letter-spacing: 0.5440000295639038px;text-align: center;max-width: 100%;color: rgb(255, 41, 65);line-height: 22.4px;">（给</span><span style="font-size: 14px;letter-spacing: 0.5440000295639038px;text-align: center;max-width: 100%;line-height: 22.4px;color: rgb(0, 128, 255);">ImportNew</span><span style="font-size: 14px;letter-spacing: 0.5440000295639038px;text-align: center;max-width: 100%;color: rgb(255, 41, 65);line-height: 22.4px;">加星标，提高Java技能）</span></p> <blockquote> <p style="letter-spacing: 0.5440000295639038px;white-space: normal;background-color: rgb(255, 255, 255);max-width: 100%;min-height: 1em;text-align: left;box-sizing: border-box !important;overflow-wrap: break-word !important;"><span style="max-width: 100%;font-size: 14px;box-sizing: border-box !important;overflow-wrap: break-word !important;">转自：<span style="color: rgb(154, 154, 154);font-size: 14px;letter-spacing: 0.544px;text-align: left;background-color: rgb(255, 255, 255);">陶章</span><span style="color: rgb(154, 154, 154);font-size: 14px;letter-spacing: 0.544px;text-align: left;background-color: rgb(255, 255, 255);">好</span></span></p> <p style="letter-spacing: 0.5440000295639038px;white-space: normal;background-color: rgb(255, 255, 255);max-width: 100%;min-height: 1em;text-align: left;box-sizing: border-box !important;overflow-wrap: break-word !important;"><span style="font-size: 14px;letter-spacing: 0.544px;">链接：</span><span style="font-size: 14px;letter-spacing: 0.544px;">https://juejin.im/post/5d026212f265da1b8608828b</span></p> </blockquote> <p style="text-align: left;"><span style="font-size: 15px;">Idea是Java开发利器，SpringBoot是Java生态中最流行的微服务框架，docker是时下最火的容器技术，那么它们结合在一起会产生什么化学反应呢？</span><br></p> <p style="text-align: left;"><span style="font-size: 16px;font-family: Optima-Regular, PingFangTC-light;"><br></span></p> <h2 data-id="heading-0" style="text-align: left;"><span style="color: rgb(171, 25, 66);"><strong><span style="color: rgb(171, 25, 66);font-size: 15px;text-align: left;">一、开发前准备</span></strong></span></h2> <p><strong><span style="font-size: 16px;font-family: Optima-Regular, PingFangTC-light;"><br></span></strong></p> <h4 data-id="heading-1" style="text-align: left;"><span style="font-size: 15px;">1. Docker的安装可以参考https://docs.docker.com/install/</span></h4> <h4 data-id="heading-2" style="text-align: left;"><br></h4> <h4 data-id="heading-2" style="text-align: left;"><span style="font-size: 15px;">2. 配置docker远程连接端口</span></h4> <section class="code-snippet__fix code-snippet__js"> <ul class="code-snippet__line-index code-snippet__js"> </ul> <pre class="code-snippet__js" data-lang="nginx"><code><span class="code-snippet_outer"> <span class="code-snippet__attribute">vi</span> /usr/lib/systemd/system/docker.service</span></code></pre> </section> <p style="text-align: left;"><span style="font-size: 15px;"><br>找到 ExecStart，在最后面添加 -H tcp://0.0.0.0:2375，如下图所示</span></p> <p><br></p> <figure style="text-align: left;"> <br> </figure> <figure style="text-align: center;"> <img data-height="284" data-ratio="0.37270341207349084" src="/upload/b57961482942917e3ba0845ef85cede0.png" data-type="other" data-w="762" data-width="762"> </figure> <p><br></p> <p><br></p> <h4 data-id="heading-3" style="text-align: left;"><span style="font-size: 15px;">3. 重启docker</span></h4> <section class="code-snippet__fix code-snippet__js"> <ul class="code-snippet__line-index code-snippet__js"> </ul> <pre class="code-snippet__js" data-lang="properties"><code><span class="code-snippet_outer"> <span class="code-snippet__attr">systemctl</span> <span class="code-snippet__string">daemon-reload</span></span></code><code><span class="code-snippet_outer"> <span class="code-snippet__attr">systemctl</span> <span class="code-snippet__string">start docker</span></span></code></pre> </section> <pre style="text-align: left;"><br></pre> <h4 data-id="heading-4" style="text-align: left;"><span style="font-size: 15px;">4. 开放端口</span></h4> <section class="code-snippet__fix code-snippet__js"> <ul class="code-snippet__line-index code-snippet__js"> </ul> <pre class="code-snippet__js" data-lang="cs"><code><span class="code-snippet_outer">firewall-cmd --zone=<span class="code-snippet__keyword">public</span> --<span class="code-snippet__keyword">add</span>-port=<span class="code-snippet__number">2375</span>/tcp --permanent</span></code></pre> </section> <pre style="text-align: left;"><span style="font-size: 16px;font-family: Optima-Regular, PingFangTC-light;"></span><br></pre> <h4 data-id="heading-5" style="text-align: left;"><span style="font-size: 15px;">5. Idea安装插件,重启</span></h4> <p style="text-align: left;"><br></p> <figure style="text-align: center;"> <img data-height="722" data-ratio="0.5846153846153846" src="/upload/4c0fe35d9247f0afaa9cce322e59f99e.png" data-type="other" data-w="1235" data-width="1235"> </figure> <p><br></p> <h4 data-id="heading-6" style="text-align: left;">6. 连接远程docker</h4> <p><span style="font-size: 16px;font-family: Optima-Regular, PingFangTC-light;background-color: rgb(255, 218, 169);"><br></span></p> <h4 data-id="heading-7" style="text-align: left;"><span style="font-size: 16px;font-family: Optima-Regular, PingFangTC-light;">&nbsp;(1) 编辑配置</span></h4> <figure style="text-align: center;"> <img data-height="180" data-ratio="0.40089086859688194" src="/upload/888629629d3e852d787e8d7ddae186ad.png" data-type="other" data-w="449" data-width="449"> </figure> <h4 data-id="heading-8" style="text-align: left;"><span style="font-size: 16px;font-family: Optima-Regular, PingFangTC-light;">  </span></h4> <h4 data-id="heading-8" style="text-align: left;"><span style="font-size: 16px;font-family: Optima-Regular, PingFangTC-light;"> (2) 填远程docker地址</span></h4> <figure style="text-align: center;"> <img data-height="545" data-ratio="1.1822125813449025" src="/upload/c13714005b1bb4428ce56dc4c4384afb.png" data-type="other" data-w="461" data-width="461"> </figure> <h4 data-id="heading-9" style="text-align: left;"><br></h4> <h4 data-id="heading-9" style="text-align: left;"><span style="font-size: 16px;font-family: Optima-Regular, PingFangTC-light;">&nbsp;(3) 连接成功，会列出远程docker容器和镜像</span></h4> <figure style="text-align: left;"> <img data-height="215" data-ratio="0.20692974013474494" src="/upload/144c00e4dd0a948e9d3891deb4f68f21.png" data-type="other" data-w="1039" data-width="1039"> </figure> <p><br></p> <h2 data-id="heading-10" style="text-align: left;"><span style="color: rgb(171, 25, 66);"><strong><span style="color: rgb(171, 25, 66);font-size: 15px;text-align: left;">二、新建项目</span></strong></span><span style="font-size: 16px;font-family: Optima-Regular, PingFangTC-light;"></span></h2> <p style="text-align: left;"><br></p> <h4 data-id="heading-11" style="text-align: left;">1. 创建springboot项目</h4> <p><span style="font-size: 16px;font-family: Optima-Regular, PingFangTC-light;background-color: rgb(255, 218, 169);"><br></span></p> <p style="text-align: left;"><span style="font-size: 16px;font-family: Optima-Regular, PingFangTC-light;">项目结构图</span></p> <p><br></p> <figure style="text-align: center;"> <img data-height="384" data-ratio="1.0971428571428572" src="/upload/47340598350e7a9fb0c1cc8f2aa1ce0d.png" data-type="other" data-w="350" data-width="350"> </figure> <p><br></p> <h4 data-id="heading-12" style="text-align: left;">(1) 配置pom文件</h4> <section class="code-snippet__fix code-snippet__js"> <ul class="code-snippet__line-index code-snippet__js"> </ul> <pre class="code-snippet__js" data-lang="xml"><code><span class="code-snippet_outer"><span class="code-snippet__meta">&lt;?xml version="1.0" encoding="UTF-8"?&gt;</span></span></code><code><span class="code-snippet_outer"><span class="code-snippet__tag">&lt;<span class="code-snippet__name">project</span> <span class="code-snippet__attr">xmlns</span>=<span class="code-snippet__string">"http://maven.apache.org/POM/4.0.0"</span></span></span></code><code><span class="code-snippet_outer"> <span class="code-snippet__attr">xmlns:xsi</span>=<span class="code-snippet__string">"http://www.w3.org/2001/XMLSchema-instance"</span></span></code><code><span class="code-snippet_outer"> <span class="code-snippet__attr">xsi:schemaLocation</span>=<span class="code-snippet__string">"http://maven.apache.org/POM/4.0.0 http://maven.apache.org/xsd/maven-4.0.0.xsd"</span>&gt;</span></code><code><span class="code-snippet_outer"> <span class="code-snippet__tag">&lt;<span class="code-snippet__name">modelVersion</span>&gt;</span>4.0.0<span class="code-snippet__tag">&lt;/<span class="code-snippet__name">modelVersion</span>&gt;</span></span></code><code><span class="code-snippet_outer"><br></span></code><code><span class="code-snippet_outer"> <span class="code-snippet__tag">&lt;<span class="code-snippet__name">groupId</span>&gt;</span>docker-demo<span class="code-snippet__tag">&lt;/<span class="code-snippet__name">groupId</span>&gt;</span></span></code><code><span class="code-snippet_outer"> <span class="code-snippet__tag">&lt;<span class="code-snippet__name">artifactId</span>&gt;</span>com.demo<span class="code-snippet__tag">&lt;/<span class="code-snippet__name">artifactId</span>&gt;</span></span></code><code><span class="code-snippet_outer"> <span class="code-snippet__tag">&lt;<span class="code-snippet__name">version</span>&gt;</span>1.0-SNAPSHOT<span class="code-snippet__tag">&lt;/<span class="code-snippet__name">version</span>&gt;</span></span></code><code><span class="code-snippet_outer"> <span class="code-snippet__tag">&lt;<span class="code-snippet__name">parent</span>&gt;</span></span></code><code><span class="code-snippet_outer"> <span class="code-snippet__tag">&lt;<span class="code-snippet__name">groupId</span>&gt;</span>org.springframework.boot<span class="code-snippet__tag">&lt;/<span class="code-snippet__name">groupId</span>&gt;</span></span></code><code><span class="code-snippet_outer"> <span class="code-snippet__tag">&lt;<span class="code-snippet__name">artifactId</span>&gt;</span>spring-boot-starter-parent<span class="code-snippet__tag">&lt;/<span class="code-snippet__name">artifactId</span>&gt;</span></span></code><code><span class="code-snippet_outer"> <span class="code-snippet__tag">&lt;<span class="code-snippet__name">version</span>&gt;</span>2.0.2.RELEASE<span class="code-snippet__tag">&lt;/<span class="code-snippet__name">version</span>&gt;</span></span></code><code><span class="code-snippet_outer"> <span class="code-snippet__tag">&lt;<span class="code-snippet__name">relativePath</span> /&gt;</span></span></code><code><span class="code-snippet_outer"> <span class="code-snippet__tag">&lt;/<span class="code-snippet__name">parent</span>&gt;</span></span></code><code><span class="code-snippet_outer"><br></span></code><code><span class="code-snippet_outer"> <span class="code-snippet__tag">&lt;<span class="code-snippet__name">properties</span>&gt;</span></span></code><code><span class="code-snippet_outer"> <span class="code-snippet__tag">&lt;<span class="code-snippet__name">project.build.sourceEncoding</span>&gt;</span>UTF-8<span class="code-snippet__tag">&lt;/<span class="code-snippet__name">project.build.sourceEncoding</span>&gt;</span></span></code><code><span class="code-snippet_outer"> <span class="code-snippet__tag">&lt;<span class="code-snippet__name">project.reporting.outputEncoding</span>&gt;</span>UTF-8<span class="code-snippet__tag">&lt;/<span class="code-snippet__name">project.reporting.outputEncoding</span>&gt;</span></span></code><code><span class="code-snippet_outer"> <span class="code-snippet__tag">&lt;<span class="code-snippet__name">docker.image.prefix</span>&gt;</span>com.demo<span class="code-snippet__tag">&lt;/<span class="code-snippet__name">docker.image.prefix</span>&gt;</span></span></code><code><span class="code-snippet_outer"> <span class="code-snippet__tag">&lt;<span class="code-snippet__name">java.version</span>&gt;</span>1.8<span class="code-snippet__tag">&lt;/<span class="code-snippet__name">java.version</span>&gt;</span></span></code><code><span class="code-snippet_outer"> <span class="code-snippet__tag">&lt;/<span class="code-snippet__name">properties</span>&gt;</span></span></code><code><span class="code-snippet_outer"> <span class="code-snippet__tag">&lt;<span class="code-snippet__name">build</span>&gt;</span></span></code><code><span class="code-snippet_outer"> <span class="code-snippet__tag">&lt;<span class="code-snippet__name">plugins</span>&gt;</span></span></code><code><span class="code-snippet_outer"> <span class="code-snippet__tag">&lt;<span class="code-snippet__name">plugin</span>&gt;</span></span></code><code><span class="code-snippet_outer"> <span class="code-snippet__tag">&lt;<span class="code-snippet__name">groupId</span>&gt;</span>org.springframework.boot<span class="code-snippet__tag">&lt;/<span class="code-snippet__name">groupId</span>&gt;</span></span></code><code><span class="code-snippet_outer"> <span class="code-snippet__tag">&lt;<span class="code-snippet__name">artifactId</span>&gt;</span>spring-boot-maven-plugin<span class="code-snippet__tag">&lt;/<span class="code-snippet__name">artifactId</span>&gt;</span></span></code><code><span class="code-snippet_outer"> <span class="code-snippet__tag">&lt;/<span class="code-snippet__name">plugin</span>&gt;</span></span></code><code><span class="code-snippet_outer"> <span class="code-snippet__tag">&lt;<span class="code-snippet__name">plugin</span>&gt;</span></span></code><code><span class="code-snippet_outer"> <span class="code-snippet__tag">&lt;<span class="code-snippet__name">groupId</span>&gt;</span>com.spotify<span class="code-snippet__tag">&lt;/<span class="code-snippet__name">groupId</span>&gt;</span></span></code><code><span class="code-snippet_outer"> <span class="code-snippet__tag">&lt;<span class="code-snippet__name">artifactId</span>&gt;</span>docker-maven-plugin<span class="code-snippet__tag">&lt;/<span class="code-snippet__name">artifactId</span>&gt;</span></span></code><code><span class="code-snippet_outer"> <span class="code-snippet__tag">&lt;<span class="code-snippet__name">version</span>&gt;</span>1.0.0<span class="code-snippet__tag">&lt;/<span class="code-snippet__name">version</span>&gt;</span></span></code><code><span class="code-snippet_outer"> <span class="code-snippet__tag">&lt;<span class="code-snippet__name">configuration</span>&gt;</span></span></code><code><span class="code-snippet_outer"> <span class="code-snippet__tag">&lt;<span class="code-snippet__name">dockerDirectory</span>&gt;</span>src/main/docker<span class="code-snippet__tag">&lt;/<span class="code-snippet__name">dockerDirectory</span>&gt;</span></span></code><code><span class="code-snippet_outer"> <span class="code-snippet__tag">&lt;<span class="code-snippet__name">resources</span>&gt;</span></span></code><code><span class="code-snippet_outer"> <span class="code-snippet__tag">&lt;<span class="code-snippet__name">resource</span>&gt;</span></span></code><code><span class="code-snippet_outer"> <span class="code-snippet__tag">&lt;<span class="code-snippet__name">targetPath</span>&gt;</span>/<span class="code-snippet__tag">&lt;/<span class="code-snippet__name">targetPath</span>&gt;</span></span></code><code><span class="code-snippet_outer"> <span class="code-snippet__tag">&lt;<span class="code-snippet__name">directory</span>&gt;</span>${project.build.directory}<span class="code-snippet__tag">&lt;/<span class="code-snippet__name">directory</span>&gt;</span></span></code><code><span class="code-snippet_outer"> <span class="code-snippet__tag">&lt;<span class="code-snippet__name">include</span>&gt;</span>${project.build.finalName}.jar<span class="code-snippet__tag">&lt;/<span class="code-snippet__name">include</span>&gt;</span></span></code><code><span class="code-snippet_outer"> <span class="code-snippet__tag">&lt;/<span class="code-snippet__name">resource</span>&gt;</span></span></code><code><span class="code-snippet_outer"> <span class="code-snippet__tag">&lt;/<span class="code-snippet__name">resources</span>&gt;</span></span></code><code><span class="code-snippet_outer"> <span class="code-snippet__tag">&lt;/<span class="code-snippet__name">configuration</span>&gt;</span></span></code><code><span class="code-snippet_outer"> <span class="code-snippet__tag">&lt;/<span class="code-snippet__name">plugin</span>&gt;</span></span></code><code><span class="code-snippet_outer"> <span class="code-snippet__tag">&lt;<span class="code-snippet__name">plugin</span>&gt;</span></span></code><code><span class="code-snippet_outer"> <span class="code-snippet__tag">&lt;<span class="code-snippet__name">artifactId</span>&gt;</span>maven-antrun-plugin<span class="code-snippet__tag">&lt;/<span class="code-snippet__name">artifactId</span>&gt;</span></span></code><code><span class="code-snippet_outer"> <span class="code-snippet__tag">&lt;<span class="code-snippet__name">executions</span>&gt;</span></span></code><code><span class="code-snippet_outer"> <span class="code-snippet__tag">&lt;<span class="code-snippet__name">execution</span>&gt;</span></span></code><code><span class="code-snippet_outer"> <span class="code-snippet__tag">&lt;<span class="code-snippet__name">phase</span>&gt;</span>package<span class="code-snippet__tag">&lt;/<span class="code-snippet__name">phase</span>&gt;</span></span></code><code><span class="code-snippet_outer"> <span class="code-snippet__tag">&lt;<span class="code-snippet__name">configuration</span>&gt;</span></span></code><code><span class="code-snippet_outer"> <span class="code-snippet__tag">&lt;<span class="code-snippet__name">tasks</span>&gt;</span></span></code><code><span class="code-snippet_outer"> <span class="code-snippet__tag">&lt;<span class="code-snippet__name">copy</span> <span class="code-snippet__attr">todir</span>=<span class="code-snippet__string">"src/main/docker"</span> <span class="code-snippet__attr">file</span>=<span class="code-snippet__string">"target/${project.artifactId}-${project.version}.${project.packaging}"</span>&gt;</span><span class="code-snippet__tag">&lt;/<span class="code-snippet__name">copy</span>&gt;</span></span></code><code><span class="code-snippet_outer"> <span class="code-snippet__tag">&lt;/<span class="code-snippet__name">tasks</span>&gt;</span></span></code><code><span class="code-snippet_outer"> <span class="code-snippet__tag">&lt;/<span class="code-snippet__name">configuration</span>&gt;</span></span></code><code><span class="code-snippet_outer"> <span class="code-snippet__tag">&lt;<span class="code-snippet__name">goals</span>&gt;</span></span></code><code><span class="code-snippet_outer"> <span class="code-snippet__tag">&lt;<span class="code-snippet__name">goal</span>&gt;</span>run<span class="code-snippet__tag">&lt;/<span class="code-snippet__name">goal</span>&gt;</span></span></code><code><span class="code-snippet_outer"> <span class="code-snippet__tag">&lt;/<span class="code-snippet__name">goals</span>&gt;</span></span></code><code><span class="code-snippet_outer"> <span class="code-snippet__tag">&lt;/<span class="code-snippet__name">execution</span>&gt;</span></span></code><code><span class="code-snippet_outer"> <span class="code-snippet__tag">&lt;/<span class="code-snippet__name">executions</span>&gt;</span></span></code><code><span class="code-snippet_outer"> <span class="code-snippet__tag">&lt;/<span class="code-snippet__name">plugin</span>&gt;</span></span></code><code><span class="code-snippet_outer"><br></span></code><code><span class="code-snippet_outer"> <span class="code-snippet__tag">&lt;/<span class="code-snippet__name">plugins</span>&gt;</span></span></code><code><span class="code-snippet_outer"> <span class="code-snippet__tag">&lt;/<span class="code-snippet__name">build</span>&gt;</span></span></code><code><span class="code-snippet_outer"><span class="code-snippet__tag">&lt;<span class="code-snippet__name">dependencies</span>&gt;</span></span></code><code><span class="code-snippet_outer"> <span class="code-snippet__tag">&lt;<span class="code-snippet__name">dependency</span>&gt;</span></span></code><code><span class="code-snippet_outer"> <span class="code-snippet__tag">&lt;<span class="code-snippet__name">groupId</span>&gt;</span>org.springframework.boot<span class="code-snippet__tag">&lt;/<span class="code-snippet__name">groupId</span>&gt;</span></span></code><code><span class="code-snippet_outer"> <span class="code-snippet__tag">&lt;<span class="code-snippet__name">artifactId</span>&gt;</span>spring-boot-starter-web<span class="code-snippet__tag">&lt;/<span class="code-snippet__name">artifactId</span>&gt;</span></span></code><code><span class="code-snippet_outer"> <span class="code-snippet__tag">&lt;/<span class="code-snippet__name">dependency</span>&gt;</span></span></code><code><span class="code-snippet_outer"> <span class="code-snippet__tag">&lt;<span class="code-snippet__name">dependency</span>&gt;</span></span></code><code><span class="code-snippet_outer"> <span class="code-snippet__tag">&lt;<span class="code-snippet__name">groupId</span>&gt;</span>org.springframework.boot<span class="code-snippet__tag">&lt;/<span class="code-snippet__name">groupId</span>&gt;</span></span></code><code><span class="code-snippet_outer"> <span class="code-snippet__tag">&lt;<span class="code-snippet__name">artifactId</span>&gt;</span>spring-boot-starter-test<span class="code-snippet__tag">&lt;/<span class="code-snippet__name">artifactId</span>&gt;</span></span></code><code><span class="code-snippet_outer"> <span class="code-snippet__tag">&lt;<span class="code-snippet__name">scope</span>&gt;</span>test<span class="code-snippet__tag">&lt;/<span class="code-snippet__name">scope</span>&gt;</span></span></code><code><span class="code-snippet_outer"> <span class="code-snippet__tag">&lt;/<span class="code-snippet__name">dependency</span>&gt;</span></span></code><code><span class="code-snippet_outer"> <span class="code-snippet__tag">&lt;<span class="code-snippet__name">dependency</span>&gt;</span></span></code><code><span class="code-snippet_outer"> <span class="code-snippet__tag">&lt;<span class="code-snippet__name">groupId</span>&gt;</span>log4j<span class="code-snippet__tag">&lt;/<span class="code-snippet__name">groupId</span>&gt;</span></span></code><code><span class="code-snippet_outer"> <span class="code-snippet__tag">&lt;<span class="code-snippet__name">artifactId</span>&gt;</span>log4j<span class="code-snippet__tag">&lt;/<span class="code-snippet__name">artifactId</span>&gt;</span></span></code><code><span class="code-snippet_outer"> <span class="code-snippet__tag">&lt;<span class="code-snippet__name">version</span>&gt;</span>1.2.17<span class="code-snippet__tag">&lt;/<span class="code-snippet__name">version</span>&gt;</span></span></code><code><span class="code-snippet_outer"> <span class="code-snippet__tag">&lt;/<span class="code-snippet__name">dependency</span>&gt;</span></span></code><code><span class="code-snippet_outer"><span class="code-snippet__tag">&lt;/<span class="code-snippet__name">dependencies</span>&gt;</span></span></code><code><span class="code-snippet_outer"><span class="code-snippet__tag">&lt;/<span class="code-snippet__name">project</span>&gt;</span></span></code></pre> </section> <pre style="text-align: left;"><br></pre> <h4 data-id="heading-13" style="text-align: left;">(2) 在src/main目录下创建docker目录，并创建Dockerfile文件</h4> <p><span style="font-size: 16px;font-family: Optima-Regular, PingFangTC-light;background-color: rgb(255, 218, 169);"><br></span></p> <section class="code-snippet__fix code-snippet__js"> <ul class="code-snippet__line-index code-snippet__js"> </ul> <pre class="code-snippet__js" data-lang="nginx"><code><span class="code-snippet_outer"><span class="code-snippet__attribute">FROM</span> openjdk:<span class="code-snippet__number">8</span>-jdk-alpine</span></code><code><span class="code-snippet_outer">ADD <span class="code-snippet__regexp">*.jar</span> app.jar</span></code><code><span class="code-snippet_outer">ENTRYPOINT&nbsp;[<span class="code-snippet__string">"java"</span>,<span class="code-snippet__string">"-Djava.security.egd=file:/dev/./urandom"</span>,<span class="code-snippet__string">"-jar"</span>,<span class="code-snippet__string">"/app.jar"</span>]</span></code></pre> </section> <pre style="text-align: left;"><br></pre> <h4 data-id="heading-14" style="text-align: left;">(3) 在resource目录下创建application.properties文件</h4> <p><span style="font-size: 16px;font-family: Optima-Regular, PingFangTC-light;background-color: rgb(255, 218, 169);"><br></span></p> <section class="code-snippet__fix code-snippet__js"> <ul class="code-snippet__line-index code-snippet__js"> </ul> <pre class="code-snippet__js" data-lang="javascript"><code><span class="code-snippet_outer">logging.config=classpath:logback.xml</span></code><code><span class="code-snippet_outer">logging.path=<span class="code-snippet__regexp">/home/</span>developer/app/logs/</span></code><code><span class="code-snippet_outer">server.port=<span class="code-snippet__number">8990</span></span></code></pre> </section> <pre style="text-align: left;"><br></pre> <h4 data-id="heading-15" style="text-align: left;">(4) 创建DockerApplication文件</h4> <p><span style="font-size: 16px;font-family: Optima-Regular, PingFangTC-light;background-color: rgb(255, 218, 169);"><br></span></p> <section class="code-snippet__fix code-snippet__js"> <ul class="code-snippet__line-index code-snippet__js"> </ul> <pre class="code-snippet__js" data-lang="java"><code><span class="code-snippet_outer"><span class="code-snippet__meta">@SpringBootApplication</span></span></code><code><span class="code-snippet_outer"><span class="code-snippet__keyword">public</span> <span class="code-snippet__class"><span class="code-snippet__keyword">class</span> <span class="code-snippet__title">DockerApplication</span> </span>{</span></code><code><span class="code-snippet_outer"> <span class="code-snippet__function"><span class="code-snippet__keyword">public</span> <span class="code-snippet__keyword">static</span> <span class="code-snippet__keyword">void</span> <span class="code-snippet__title">main</span><span class="code-snippet__params">(String[] args)</span> </span>{</span></code><code><span class="code-snippet_outer"> SpringApplication.run(DockerApplication.class, args);</span></code><code><span class="code-snippet_outer"> }</span></code><code><span class="code-snippet_outer">}</span></code></pre> </section> <pre style="text-align: left;"><br></pre> <h4 data-id="heading-16" style="text-align: left;">(5) 创建DockerController文件</h4> <p><span style="font-size: 16px;font-family: Optima-Regular, PingFangTC-light;background-color: rgb(255, 218, 169);"><br></span></p> <section class="code-snippet__fix code-snippet__js"> <ul class="code-snippet__line-index code-snippet__js"> </ul> <pre class="code-snippet__js" data-lang="kotlin"><code><span class="code-snippet_outer"><span class="code-snippet__meta">@RestController</span></span></code><code><span class="code-snippet_outer"><span class="code-snippet__keyword">public</span> <span class="code-snippet__class"><span class="code-snippet__keyword">class</span> <span class="code-snippet__title">DockerController</span> </span>{</span></code><code><span class="code-snippet_outer"> static Log log = LogFactory.getLog(DockerController.<span class="code-snippet__keyword">class</span>);</span></code><code><span class="code-snippet_outer"><br></span></code><code><span class="code-snippet_outer"> <span class="code-snippet__meta">@RequestMapping(<span class="code-snippet__meta-string">"/"</span>)</span></span></code><code><span class="code-snippet_outer"> <span class="code-snippet__keyword">public</span> String index() {</span></code><code><span class="code-snippet_outer"> log.info(<span class="code-snippet__string">"Hello Docker!"</span>);</span></code><code><span class="code-snippet_outer"> <span class="code-snippet__keyword">return</span> <span class="code-snippet__string">"Hello Docker!"</span>;</span></code><code><span class="code-snippet_outer"> }</span></code><code><span class="code-snippet_outer">}</span></code></pre> </section> <pre style="text-align: left;"><br></pre> <h4 data-id="heading-17" style="text-align: left;">(6) 增加配置</h4> <p style="text-align: left;"><br></p> <figure style="text-align: center;"> <img data-height="53" data-ratio="0.27040816326530615" src="/upload/6a9937860b26f31c0139b5f84fd6733e.png" data-type="other" data-w="196" data-width="196"> </figure> <p><br></p> <figure style="text-align: center;"> <img data-height="358" data-ratio="0.7396694214876033" src="/upload/b5793e575daf529a46fe9ae0a6a3b4b8.png" data-type="other" data-w="484" data-width="484"> </figure> <p><br></p> <figure style="text-align: left;"> <img data-height="858" data-ratio="0.7907834101382488" src="/upload/580905fb089fe7268fbc534c0934877.png" data-type="other" data-w="1085" data-width="1085"> </figure> <p><br></p> <p style="text-align: left;"><strong><span style="font-family: Optima-Regular, PingFangTC-light;font-size: 16px;">命令解释</span></strong><br></p> <p style="text-align: left;"><br></p> <p style="text-align: left;"><span style="font-size: 16px;font-family: Optima-Regular, PingFangTC-light;">Image tag : 指定镜像名称和tag，镜像名称为 docker-demo，tag为1.1<br>Bind ports : 绑定宿主机端口到容器内部端口。格式为[宿主机端口]:[容器内</span><span style="font-family: Optima-Regular, PingFangTC-light;font-size: 16px;">部端口]</span></p> <p style="text-align: left;"><span style="font-size: 16px;font-family: Optima-Regular, PingFangTC-light;">Bind mounts : 将宿主机目录挂到到容器内部目录中。格式为[宿主机目录]:[容器内部目录]。这个springboot项目会将日志打印在容器&nbsp;</span></p> <p style="text-align: left;"><span style="font-size: 16px;font-family: Optima-Regular, PingFangTC-light;">/home/developer/app/logs/ 目录下，将宿主机目录挂载到容器内部目录后，那么日志就会持久化容器外部的宿主机目录中。</span></p> <p style="text-align: left;"><span style="font-size: 16px;font-family: Optima-Regular, PingFangTC-light;"><br></span></p> <h4 data-id="heading-18" style="text-align: left;">(7) Maven打包</h4> <p><span style="font-size: 16px;font-family: Optima-Regular, PingFangTC-light;background-color: rgb(255, 218, 169);"><br></span></p> <figure style="text-align: center;"> <img data-height="474" data-ratio="1.3581661891117478" src="/upload/3e1d71e00086603d885cb6c7db8e3184.png" data-type="other" data-w="349" data-width="349"> </figure> <p><br></p> <h4 data-id="heading-19" style="text-align: left;">(8) 运行</h4> <p style="text-align: left;"><br></p> <figure style="text-align: center;"> <img data-height="48" data-ratio="0.17454545454545456" src="/upload/4c21ad1e01b5a8ac8f7a163e51d8f7e4.png" data-type="other" data-w="275" data-width="275"> </figure> <figure style="text-align: center;"> <img data-height="672" data-ratio="0.525" src="/upload/9fe010456406cb97ac5736ef8c9f915c.png" data-type="other" data-w="1280" data-width="1280"> </figure> <p style="text-align: left;"><br></p> <p style="text-align: left;"><span style="font-size: 16px;font-family: Optima-Regular, PingFangTC-light;">先pull基础镜像，然后再打包镜像，并将镜像部署到远程docker运行</span></p> <p style="text-align: left;"><span style="font-size: 16px;font-family: Optima-Regular, PingFangTC-light;"><br></span></p> <figure style="text-align: center;"> <img data-height="663" data-ratio="0.51875" src="/upload/b5bcc1b0c2c7d255d42b9e8c83d5a113.png" data-type="other" data-w="1280" data-width="1280"> </figure> <p style="text-align: left;"><span style="font-size: 16px;font-family: Optima-Regular, PingFangTC-light;">这里我们可以看到镜像名称为docker-demo:1.1，docker容器为docker-server</span></p> <p><br></p> <h4 data-id="heading-20" style="text-align: left;">(9) 运行成功</h4> <p style="text-align: left;"><br></p> <figure style="text-align: left;"> <img data-height="709" data-ratio="0.7607296137339056" src="/upload/9725fd31a2952526a55ff4177275c0bf.png" data-type="other" data-w="932" data-width="932"> </figure> <p><br></p> <h4 data-id="heading-21" style="text-align: left;">(10) 浏览器访问</h4> <p style="text-align: left;"><br></p> <figure style="text-align: center;"> <img data-height="163" data-ratio="0.3140655105973025" src="/upload/e5f7a84d3e8aaceaf5dd1e43435ef62d.png" data-type="other" data-w="519" data-width="519"> </figure> <p style="text-align: left;">(11) 日志查看</p> <p><br></p> <figure style="text-align: center;"> <img data-height="62" data-ratio="0.22794117647058823" src="/upload/cc2bd9a98effd5deed1efc024d0e7709.png" data-type="other" data-w="272" data-width="272"> </figure> <p><br></p> <p style="text-align: left;"><span style="font-size: 16px;font-family: Optima-Regular, PingFangTC-light;">自此通过idea 部署springboot项目到docker成功！难以想象，部署一个Javaweb项目竟然如此简单方便！</span></p> <p style="white-space: normal;"><br></p> <section donone="shifuMouseDownCard('shifu_c_030')" label="Copyright Reserved by PLAYHUDONG." style="margin-top: 1em;margin-bottom: 1em;white-space: normal;text-align: start;color: rgb(0, 0, 0);border-width: 0px;border-style: initial;border-color: initial;"> <section style="margin-left: 1em;line-height: 1.4;"> <span style="padding: 3px 8px;border-radius: 4px;color: rgb(255, 255, 255);background-color: rgb(255, 105, 31);font-family: inherit;text-align: inherit;text-decoration: inherit;font-size: 16px;">推荐阅读</span>&nbsp;&nbsp; <span style="margin-left: 4px;padding: 3px 8px;border-radius: 1.2em;color: rgb(255, 255, 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<section style="line-height: 1.75em;" data-mpa-powered-by="yiban.io"> <span style="font-size: 15px;letter-spacing: 1px;">职业生涯的前五年，基本上都在做<strong>即时通讯</strong>业务，由于业务的特殊性，吞吐量极大，时延不这么敏感，团队内部单独开发了一套纯异步omni框架。</span> </section> <section style="line-height: 1.75em;"> <span style="font-size: 15px;letter-spacing: 1px;">&nbsp;</span> </section> <section style="line-height: 1.75em;"> <span style="font-size: 15px;letter-spacing: 1px;">学习omni框架内核，对职业生涯的提升极大，<strong>协议设计与实现</strong>，<strong>底层网络通信</strong>，<strong>多线程同步与互斥</strong>，<strong>同步RPC</strong>，<strong>异步RPC</strong>，<strong>服务器框架</strong>… 掌握了一套RPC内核原理与细节，基本上国内大部分公司的offer能手到擒来。</span> </section> <section style="line-height: 1.75em;"> <span style="font-size: 15px;letter-spacing: 1px;">&nbsp;</span> </section> <section style="line-height: 1.75em;"> <strong><span style="font-size: 15px;letter-spacing: 1px;">很多朋友问，如何学习RPC内核知识？</span></strong> </section> <section style="line-height: 1.75em;"> <span style="font-size: 15px;letter-spacing: 1px;">我的回答是，</span> <span style="font-size: 15px;letter-spacing: 1px;color: rgb(255, 76, 0);">直接看源码</span> <span style="font-size: 15px;letter-spacing: 1px;">。</span> </section> <section style="line-height: 1.75em;"> <br> </section> <section style="line-height: 1.75em;"> <span style="font-size: 15px;letter-spacing: 1px;">代码面前，没有秘密，<strong>看源码，写demo，单步调试</strong>，比听任何大神吹牛，比看任何理论书籍，都来得直接。</span> </section> <section style="line-height: 1.75em;"> <span style="font-size: 15px;letter-spacing: 1px;">&nbsp;</span> </section> <section style="line-height: 1.75em;"> <strong><span style="font-size: 15px;letter-spacing: 1px;">又有朋友问，目前开源的brpc以及thrift，都太重了，有没有更轻量级的服务端框架呢？</span></strong> <span style="font-size: 15px;letter-spacing: 1px;"></span> </section> <section style="line-height: 1.75em;"> <span style="font-size: 15px;letter-spacing: 1px;">这里，我强烈推荐，</span> <span style="font-size: 15px;letter-spacing: 1px;color: rgb(255, 76, 0);">搜狗开源的轻量级高性能服务器引擎WF</span> <span style="font-size: 15px;letter-spacing: 1px;">：</span> </section> <section style="line-height: 1.75em;"> <span style="font-size: 15px;letter-spacing: 1px;">（1）看其代码，及其清爽易懂；</span> </section> <section style="line-height: 1.75em;"> <span style="font-size: 15px;letter-spacing: 1px;">（2）demo简单，单步调试容易；</span> </section> <section style="line-height: 1.75em;"> <span style="font-size: 15px;letter-spacing: 1px;">（3）doc比较全，doc与src同步更新，比起行业内一些“为了开源而开源”的KPI项目，显得有诚意多了；</span> </section> <section style="line-height: 1.75em;"> <span style="font-size: 15px;letter-spacing: 1px;"><br></span> </section> <section style="line-height: 1.75em;"> <span style="font-size: 15px;letter-spacing: 1px;">个人觉得搜狗的WF框架，是目前国内开源的服务器引擎中<strong>最适合学习的</strong>。</span> </section> <section style="line-height: 1.75em;"> <span style="color: rgb(0, 128, 255);"><em><span style="font-size: 15px;letter-spacing: 1px;">画外音：文末有github地址。</span></em></span> </section> <section style="line-height: 1.75em;"> <span style="font-size: 15px;letter-spacing: 1px;">&nbsp;</span> </section> <section style="line-height: 1.75em;"> <span style="font-size: 15px;letter-spacing: 1px;">这里，把自己的学习心得，以及大家可能关心的问题，简单聊一聊。</span> </section> <section style="line-height: 1.75em;"> <span style="font-size: 15px;letter-spacing: 1px;">&nbsp;</span> </section> <section style="line-height: 1.75em;"> <strong><span style="font-size: 15px;letter-spacing: 1px;">什么是WF，它是一个娱乐级框架，还是一个工业级框架？</span></strong> <span style="font-size: 15px;letter-spacing: 1px;"></span> </section> <section style="line-height: 1.75em;"> <span style="font-size: 15px;letter-spacing: 1px;">WF，是搜狗开源的C++服务器引擎框架。</span> </section> <section style="line-height: 1.75em;"> <span style="font-size: 15px;letter-spacing: 1px;">&nbsp;</span> </section> <section style="line-height: 1.75em;"> <strong><span style="font-size: 15px;letter-spacing: 1px;">WF的设计目标是</span></strong> <span style="font-size: 15px;letter-spacing: 1px;">：</span> <span style="font-size: 15px;letter-spacing: 1px;color: rgb(255, 76, 0);">轻量级，高性能</span> <span style="font-size: 15px;letter-spacing: 1px;">。</span> </section> <section style="line-height: 1.75em;"> <span style="font-size: 15px;letter-spacing: 1px;">&nbsp;</span> </section> <section style="line-height: 1.75em;"> <span style="font-size: 15px;letter-spacing: 1px;">轻量级，是指简洁，搜狗几乎所有的C++后端服务，包含但不限于搜索，输入法，广告等都是基于这个框架，每天处理超过百亿的请求，它是一个已经<strong>经过多年线上考验的工业级框架</strong>。</span> </section> <section style="line-height: 1.75em;"> <span style="font-size: 15px;letter-spacing: 1px;">&nbsp;</span> </section> <section style="line-height: 1.75em;"> <strong><span style="font-size: 15px;letter-spacing: 1px;">轻量级， WF真的做到了吗？</span></strong> <span style="font-size: 15px;letter-spacing: 1px;"></span> </section> <section style="line-height: 1.75em;"> <span style="font-size: 15px;letter-spacing: 1px;">大伙可以看下，用WF如何搭建http服务器：</span> </section> <p style="text-align: center;"><img class="rich_pages js_insertlocalimg" data-ratio="0.4694708276797829" data-s="300,640" src="/upload/c285fe29c7671b8d7516d09bba9ac911.png" data-type="png" data-w="737" style=""></p> <section style="line-height: 1.75em;"> <span style="font-size: 15px;letter-spacing: 1px;">这一段代码单步执行下来，IO线程，工作线程，任务队列，线程同步互斥机制，超时处理机制，异常处理机制… 对于一个服务器框架，基本就拿下七八成。</span> <br> </section> <section style="line-height: 1.75em;"> <span style="font-size: 15px;letter-spacing: 1px;">&nbsp;</span> </section> <section style="line-height: 1.75em;"> <strong><span style="font-size: 15px;letter-spacing: 1px;">高性能，WF真的做到了吗？</span></strong> <span style="font-size: 15px;letter-spacing: 1px;"></span> </section> <section style="line-height: 1.75em;"> <span style="font-size: 15px;letter-spacing: 1px;">大伙可以看下，WF的单机压测表现：</span> </section> <p style="text-align: center;"><img class="rich_pages js_insertlocalimg" data-ratio="0.6023809523809524" data-s="300,640" src="/upload/e8b3162f817e381c6a896d3b4cf0312a.png" data-type="png" data-w="840" style=""></p> <section style="line-height: 1.75em;"> <span style="font-size: 15px;letter-spacing: 1px;">你没有看错，单机每秒50W的QPS，特别是高并发压测的情况下，比nginx和brpc表现都要好。</span> <br> </section> <section style="line-height: 1.75em;"> <span style="color: rgb(0, 128, 255);"><em><span style="font-size: 15px;letter-spacing: 1px;">画外音：</span></em></span> </section> <section style="line-height: 1.75em;"> <span style="color: rgb(0, 128, 255);"><em><span style="font-size: 15px;letter-spacing: 1px;">（1）测试硬件：CPU 40 core @ 2.20GHz，内存192G，网卡25000Mb/s；</span></em></span> </section> <section style="line-height: 1.75em;"> <span style="color: rgb(0, 128, 255);"><em><span style="font-size: 15px;letter-spacing: 1px;">（2）并发配置：nginx auto进程数为40，brpc配置nthreads为40，WF配置16个poller线程与20个handler线程；</span></em></span> </section> <section style="line-height: 1.75em;"> <span style="font-size: 15px;letter-spacing: 1px;">&nbsp;</span> </section> <section style="line-height: 1.75em;"> <strong><span style="font-size: 15px;letter-spacing: 1px;">除了轻量级与高性能，WF还有哪些特点？</span></strong> <span style="font-size: 15px;letter-spacing: 1px;"></span> </section> <section style="line-height: 1.75em;"> <br> </section> <section style="line-height: 1.75em;"> <span style="font-size: 15px;letter-spacing: 1px;">除了核心设计目标的两点，WF还有以下优势：</span> </section> <section style="line-height: 1.75em;"> <strong><span style="font-size: 15px;letter-spacing: 1px;">（1）易用性</span></strong> <span style="font-size: 15px;letter-spacing: 1px;"></span> </section> <section style="line-height: 1.75em;"> <span style="font-size: 15px;letter-spacing: 1px;">相比go语言的简单，天下苦C++久矣，虽然C++后续也推出了各种简易用法，但并不是所有用户了解与掌握，目前WF的标准是C++11，把很多复杂性都进行了屏蔽。</span> </section> <section style="line-height: 1.75em;"> <span style="font-size: 15px;letter-spacing: 1px;">&nbsp;</span> </section> <section style="line-height: 1.75em;"> <span style="font-size: 15px;letter-spacing: 1px;">用户再也不用关注连接池、线程池、文件句柄，以及各种异步通知机制，WF都进行了封装与细节屏蔽。</span> </section> <section style="line-height: 1.75em;"> <span style="font-size: 15px;letter-spacing: 1px;">&nbsp;</span> </section> <section style="line-height: 1.75em;"> <span style="font-size: 15px;letter-spacing: 1px;">使用WF，<strong>用户只需要关注两个核心概念</strong>：<strong>任务</strong></span> <span style="letter-spacing: 1px;font-size: 12px;">（task）</span> <span style="font-size: 15px;letter-spacing: 1px;">与<strong>任务流</strong></span> <span style="letter-spacing: 1px;font-size: 12px;">（series）</span> <span style="font-size: 15px;letter-spacing: 1px;">。</span> </section> <section style="line-height: 1.75em;"> <span style="font-size: 15px;letter-spacing: 1px;">&nbsp;</span> </section> <section style="line-height: 1.75em;"> <strong><span style="font-size: 15px;letter-spacing: 1px;">（2）通信与计算一体的解决方案</span></strong> <span style="font-size: 15px;letter-spacing: 1px;"></span> </section> <section style="line-height: 1.75em;"> <span style="font-size: 15px;letter-spacing: 1px;">大部分RPC框架着重解决通信的问题，而计算与任务调度框架需要用户自己实现，而WF框架则将二者融为一体，一并解决了。</span> </section> <section style="line-height: 1.75em;"> <span style="font-size: 15px;letter-spacing: 1px;">&nbsp;</span> </section> <section style="line-height: 1.75em;"> <span style="font-size: 15px;letter-spacing: 1px;">WF把网络，CPU，磁盘IO，GPU，计时器，计数器都进行了封装，统一当成资源，使用者可以任意进行调度与组合，而不需要关注其底层的epoll，pthread，aio，cuda，timer_fd，count计数等。</span> </section> <section style="line-height: 1.75em;"> <span style="font-size: 15px;letter-spacing: 1px;">&nbsp;</span> </section> <section style="line-height: 1.75em;"> <strong><span style="font-size: 15px;letter-spacing: 1px;">（3）架构层次良好，非常方便业务逻辑的实现</span></strong> <span style="font-size: 15px;letter-spacing: 1px;"></span> </section> <section style="line-height: 1.75em;"> <span style="font-size: 15px;letter-spacing: 1px;">WF对于业务逻辑处理进行了抽象：</span> </section> <section style="line-height: 1.75em;"> <span style="font-size: 15px;letter-spacing: 1px;">第一，串行由任务组成；</span> </section> <section style="line-height: 1.75em;"> <span style="font-size: 15px;letter-spacing: 1px;">第二，并行由串行组成；</span> </section> <section style="line-height: 1.75em;"> <span style="font-size: 15px;letter-spacing: 1px;">第三，并行是一种任务；</span> </section> <section style="line-height: 1.75em;"> <span style="font-size: 15px;letter-spacing: 1px;">&nbsp;</span> </section> <section style="line-height: 1.75em;"> <span style="font-size: 15px;letter-spacing: 1px;">任务和任务流是WF的基石，WF本身就是一套完备的、可以收敛的、容易控制的业务逻辑任务流模型。</span> </section> <section style="line-height: 1.75em;"> <span style="font-size: 15px;letter-spacing: 1px;">&nbsp;</span> </section> <section style="line-height: 1.75em;"> <strong><span style="font-size: 15px;letter-spacing: 1px;">（4）文档很全</span></strong> <span style="font-size: 15px;letter-spacing: 1px;"></span> </section> <section style="line-height: 1.75em;"> <span style="font-size: 15px;letter-spacing: 1px;">除了轻量级，简单易用之外，其文档和demo非常齐全，对于新手及其友好。而且碰到代码中不明白的地方，可以直接联系开发小组，作者会直接和大家交流，避免二手消息。</span> </section> <p style="text-align: center;"><img class="rich_pages js_insertlocalimg" data-ratio="0.52578125" data-s="300,640" src="/upload/145c7aff32e5b825e3bad6faaec9c10a.png" data-type="png" data-w="1280" style=""></p> <section style="line-height: 1.75em;"> <span style="font-size: 15px;letter-spacing: 1px;">这也是推荐WF成为大家学习上手的框架，很重要的原因。</span> <br> </section> <section style="line-height: 1.75em;"> <span style="font-size: 15px;letter-spacing: 1px;">&nbsp;</span> </section> <section style="line-height: 1.75em;"> <strong><span style="font-size: 15px;letter-spacing: 1px;">可能有朋友会问，说框架太宏观，研究WF，具体能学到哪些技术内容呢？</span></strong> <span style="font-size: 15px;letter-spacing: 1px;"></span> </section> <section style="line-height: 1.75em;"> <br> </section> <section style="line-height: 1.75em;"> <span style="font-size: 15px;letter-spacing: 1px;">简单的举几个例子：</span> </section> <section style="line-height: 1.75em;"> <span style="font-size: 15px;letter-spacing: 1px;">（1）<strong>学习错误处理</strong>：为了提升性能，WF没有使用异常，研究WF能系统性学习错误处理，帮助我们写出极高质量的代码；</span> </section> <section style="line-height: 1.75em;"> <span style="color: rgb(0, 128, 255);"><em><span style="color: rgb(0, 128, 255);font-size: 15px;letter-spacing: 1px;">画外音：扪心自问，去掉异常，你写的代码会不会随时崩溃。</span></em></span> </section> <section style="line-height: 1.75em;"> <span style="font-size: 15px;letter-spacing: 1px;">&nbsp;</span> </section> <section style="line-height: 1.75em;"> <span style="font-size: 15px;letter-spacing: 1px;">（2）<strong>学习超时处理</strong>：各种通信超时，任务超时，你真的理解其内核么？超时的原因与处理，WF是学习利器。</span> </section> <section style="line-height: 1.75em;"> <span style="font-size: 15px;letter-spacing: 1px;">&nbsp;</span> </section> <section style="line-height: 1.75em;"> <span style="font-size: 15px;letter-spacing: 1px;">（3）<strong>学习异步IO</strong>：Linux支持非常高效的异步IO系统调度，如何使用这些异步IO去实现框架，去封装任务，实现业务逻辑任务流化，看看WF的玩法。</span> </section> <section style="line-height: 1.75em;"> <span style="font-size: 15px;letter-spacing: 1px;">&nbsp;</span> </section> <section style="line-height: 1.75em;"> <span style="font-size: 15px;letter-spacing: 1px;">（4）<strong>学习协议设计</strong>：学习如何利用WF框架，实现brpc和thrift，实现自己自定义的client/server协议，实现自己的RPC系统。</span> </section> <section style="line-height: 1.75em;"> <span style="font-size: 15px;letter-spacing: 1px;">&nbsp;</span> </section> <section style="line-height: 1.75em;"> <span style="font-size: 15px;letter-spacing: 1px;">（5）<strong>学习计时器与计数器</strong>：很有朋友timer和count用的非常多，但它底层是怎么实现的，值得深入研究。</span> </section> <section style="line-height: 1.75em;"> <span style="font-size: 15px;letter-spacing: 1px;">&nbsp;</span> </section> <section style="line-height: 1.75em;"> <span style="font-size: 15px;letter-spacing: 1px;">（6）<strong>学习服务治理</strong>：WF有一套完整的服务治理方案，包含<strong>服务路由，熔断与恢复，负载均衡，服务主备。可用于实现服务发现与服务网格</strong></span> <span style="letter-spacing: 1px;font-size: 12px;">（service mesh）</span> <span style="font-size: 15px;letter-spacing: 1px;">系统。</span> </section> <section style="line-height: 1.75em;"> <span style="color: rgb(0, 128, 255);"><em><span style="color: rgb(0, 128, 255);font-size: 15px;letter-spacing: 1px;">画外音：这一部分，可以查看源码的upstream子模块。</span></em></span> </section> <section style="line-height: 1.75em;"> <span style="font-size: 15px;letter-spacing: 1px;">&nbsp;</span> </section> <section style="line-height: 1.75em;"> <span style="font-size: 15px;letter-spacing: 1px;">（7）…</span> </section> <section style="line-height: 1.75em;"> <span style="font-size: 15px;letter-spacing: 1px;">今年，看的最清爽的代码，最适合了解通信内核，RPC内核，调度框架内核的引擎，强烈推荐给大家。</span> <span style="font-size: 15px;letter-spacing: 1px;">欢迎大家Fork，欢迎大家标星。</span> </section> <section style="line-height: 1.75em;"> <span style="font-size: 15px;letter-spacing: 1px;"><br></span> </section> <section style="line-height: 1.75em;"> <strong><span style="font-size: 15px;letter-spacing: 1px;">地址</span></strong> <span style="font-size: 15px;letter-spacing: 1px;">：https://github.com/sogou/workflow</span> </section> <section style="line-height: 1.75em;"> <strong><span style="font-size: 15px;letter-spacing: 1px;">Star</span></strong> <span style="font-size: 15px;letter-spacing: 1px;">：1400+</span> </section> <section style="line-height: 1.75em;"> <span style="color: rgb(0, 128, 255);"><em><span style="color: rgb(0, 128, 255);font-size: 15px;letter-spacing: 1px;">画外音：WF还有很多优秀的设计，等待大家去挖掘。</span></em></span> </section> <section style="line-height: 1.75em;"> <span style="font-size: 15px;letter-spacing: 1px;"></span> </section> <section style="line-height: 1.75em;"> <br> </section> <section style="line-height: 1.75em;"> <strong><span style="font-size: 15px;letter-spacing: 1px;">阅读原文</span></strong> <span style="font-size: 15px;letter-spacing: 1px;">，</span> <span style="font-size: 15px;letter-spacing: 1px;color: rgb(255, 76, 0);">直达代码</span> <span style="font-size: 15px;letter-spacing: 1px;">，<span style="font-size: 15px;letter-spacing: 1px;">好的代码，一起分享。</span></span> </section> <section style="line-height: 1.75em;"> <span style="font-size: 15px;letter-spacing: 1px;"></span> </section>

<section style="box-sizing: border-box;font-style: normal;font-weight: 400;text-align: justify;font-size: 16px;"> <section style="margin-top: 10px;margin-bottom: 10px;box-sizing: border-box;"> <section style="padding: 10px 10px 0px;background-color: rgb(239, 239, 239);box-sizing: border-box;"> <span style="display: inline-block;width: 5%;line-height: 0.8;font-weight: bolder;font-size: 48px;box-sizing: border-box;" title=""> <section style="box-sizing: border-box;"> “ </section></span> <section style="display: inline-block;vertical-align: top;float: right;width: 90%;line-height: 1.5;font-size: 15px;color: rgb(89, 89, 89);box-sizing: border-box;"> <p style="margin: 0px;padding: 0px;box-sizing: border-box;"><span style="letter-spacing: 1px;">好的代码往往也很好看！代码是给机器运行的，但同样也是给人看的，并且随着上线还需要由人来运维。那么写出可扩展、易维护、好读懂的代码就显得非常重要。</span></p> </section> <section style="clear: both;box-sizing: border-box;"> <svg viewbox="0 0 1 1" style="float:left;line-height:0;width:0;vertical-align:top;"></svg> </section> </section> </section> </section> <section style="line-height: 1.75em;"> <br> </section> <section style="text-align: center;margin-left: 8px;margin-right: 8px;"> <img class="rich_pages" data-ratio="0.664321608040201" data-s="300,640" src="/upload/9281dc23ada8977e3a01e0f06ab6e912.png" data-type="png" data-w="995" style=""> </section> <section style="text-align: center;line-height: 1.75em;"> <span style="font-size: 14px;color: rgb(89, 89, 89);letter-spacing: 1px;"><em>图片来自 Pexels</em></span> <br> </section> <section style="line-height: normal;"> <br> </section> <section data-tool="mdnice编辑器" data-website="https://www.mdnice.com"> <section data-tool="mdnice编辑器" data-website="https://www.mdnice.com"> <span style="font-size: 15px;color: rgb(89, 89, 89);letter-spacing: 1px;"></span> <p style="text-align: justify;margin-left: 8px;margin-right: 8px;line-height: 1.75em;"><span style="font-size: 15px;color: rgb(89, 89, 89);letter-spacing: 1px;">对于新人来说，互联网大厂项目开发与平常自己学习的代码还是有很大的差别的。日常学习时候通常只要能运行出结果即可，并不会有其他的要求。<br></span></p> <section style="line-height: normal;"> <br> </section> <p style="text-align: justify;margin-left: 8px;margin-right: 8px;line-height: 1.75em;"><span style="font-size: 15px;color: rgb(89, 89, 89);letter-spacing: 1px;">也不会说有；PRD 评审、研发设计评审、代码开发、代码评审以及中间一些列的提交物，直到测试完成，上线验证，开量对外等等。<br></span></p> <section style="line-height: normal;"> <br> </section> <p style="text-align: justify;margin-left: 8px;margin-right: 8px;line-height: 1.75em;"><span style="font-size: 15px;color: rgb(89, 89, 89);letter-spacing: 1px;">所以很多新人刚从学校毕业或者从小公司进入大厂，在规范制约下会有一些不习惯，甚至犯错误。<br></span></p> <section style="line-height: normal;"> <br> </section> <p style="text-align: justify;margin-left: 8px;margin-right: 8px;line-height: 1.75em;"><span style="font-size: 15px;color: rgb(89, 89, 89);letter-spacing: 1px;">那么为了让大家更好的知晓这些问题，我特意整理了一些例子，欢迎参考。<br></span></p> <section style="line-height: normal;"> <br> </section> <section style="box-sizing: border-box;font-style: normal;font-weight: 400;text-align: justify;font-size: 16px;"> <section style="border-bottom: 1px solid black;margin: 0.5em 0px;line-height: 1.2;box-sizing: border-box;"> <section style="display: inline-block;border-color: rgb(89, 89, 89);border-bottom: 6px solid rgb(89, 89, 89);margin-bottom: -1px;font-size: 20px;color: rgb(89, 89, 89);box-sizing: border-box;"> <p style="margin: 0px;padding: 0px;box-sizing: border-box;">会议室</p> </section> </section> </section> <p style="line-height: normal;"><br></p> <p style="text-align: justify;margin-left: 8px;margin-right: 8px;line-height: 1.75em;"><span style="font-size: 15px;color: rgb(89, 89, 89);letter-spacing: 1px;">谢飞机，刚刚入职没多久，兴奋的写着 Leader 给的需求，码的飞快。恰巧组长走过来：“飞机，带着你的电脑，跟我来会议室，做下代码评审。”<br></span></p> <section style="line-height: normal;"> <br> </section> <p style="text-align: justify;margin-left: 8px;margin-right: 8px;line-height: 1.75em;"><strong><span style="font-size: 15px;color: rgb(89, 89, 89);letter-spacing: 1px;">Leader：</span></strong><span style="font-size: 15px;color: rgb(89, 89, 89);letter-spacing: 1px;">飞机，你这代码咋这么粗鲁！<br></span></p> <section style="line-height: normal;"> <br> </section> <p style="text-align: justify;margin-left: 8px;margin-right: 8px;line-height: 1.75em;"><strong><span style="font-size: 15px;color: rgb(89, 89, 89);letter-spacing: 1px;">飞机：</span></strong><span style="font-size: 15px;color: rgb(89, 89, 89);letter-spacing: 1px;">啊？😱<br></span></p> <section style="line-height: normal;"> <br> </section> <p style="text-align: justify;margin-left: 8px;margin-right: 8px;line-height: 1.75em;"><strong><span style="font-size: 15px;color: rgb(89, 89, 89);letter-spacing: 1px;">Leader：</span></strong><span style="font-size: 15px;color: rgb(89, 89, 89);letter-spacing: 1px;">我要不拦着你，我感觉你这代码都能飞。<br></span></p> <section style="line-height: normal;"> <br> </section> <p style="text-align: justify;margin-left: 8px;margin-right: 8px;line-height: 1.75em;"><strong><span style="font-size: 15px;color: rgb(89, 89, 89);letter-spacing: 1px;">Leader：</span></strong><span style="font-size: 15px;color: rgb(89, 89, 89);letter-spacing: 1px;">你看哈，就说这行，这日志打的，上线后出了问题，你能查到原因吗？<br></span></p> <section style="line-height: normal;"> <br> </section> <p style="text-align: justify;margin-left: 8px;margin-right: 8px;line-height: 1.75em;"><strong><span style="font-size: 15px;color: rgb(89, 89, 89);letter-spacing: 1px;">飞机：</span></strong><span style="font-size: 15px;color: rgb(89, 89, 89);letter-spacing: 1px;">好像...<br></span></p> <section style="line-height: normal;"> <br> </section> <p style="text-align: justify;margin-left: 8px;margin-right: 8px;line-height: 1.75em;"><strong><span style="font-size: 15px;color: rgb(89, 89, 89);letter-spacing: 1px;">Leader：</span></strong><span style="font-size: 15px;color: rgb(89, 89, 89);letter-spacing: 1px;">还有这，这 idea 都提示你了，都报黄色了，你怎么不看看。还有，这代码也不格式化，一个月后它认识你，你还认识它吗。<br></span></p> <section style="line-height: normal;"> <br> </section> <p style="text-align: justify;margin-left: 8px;margin-right: 8px;line-height: 1.75em;"><strong><span style="font-size: 15px;color: rgb(89, 89, 89);letter-spacing: 1px;">Leader：</span></strong><span style="font-size: 15px;color: rgb(89, 89, 89);letter-spacing: 1px;">给你发的入职编码规范看了？<br></span></p> <section style="line-height: normal;"> <br> </section> <p style="text-align: justify;margin-left: 8px;margin-right: 8px;line-height: 1.75em;"><strong><span style="font-size: 15px;color: rgb(89, 89, 89);letter-spacing: 1px;">飞机：</span></strong><span style="font-size: 15px;color: rgb(89, 89, 89);letter-spacing: 1px;">哦，看一些，写的时候忘了。<br></span></p> <section style="line-height: normal;"> <br> </section> <p style="text-align: justify;margin-left: 8px;margin-right: 8px;line-height: 1.75em;"><strong><span style="font-size: 15px;color: rgb(89, 89, 89);letter-spacing: 1px;">Leader：</span></strong><span style="font-size: 15px;color: rgb(89, 89, 89);letter-spacing: 1px;">先别着急写，看会了再写代码，这还有一个不错的工程，可以参考。<br></span></p> <section style="line-height: normal;"> <br> </section> <p style="text-align: justify;margin-left: 8px;margin-right: 8px;line-height: 1.75em;"><span style="font-size: 15px;color: rgb(89, 89, 89);letter-spacing: 1px;">写代码不是以完成功能就算完事，还需要写的漂亮。评审后，飞机，坐回工位，收起了躁动的心，安心熟读手册并练习。<br></span></p> <p style="line-height: normal;"><br></p> <section style="box-sizing: border-box;font-style: normal;font-weight: 400;text-align: justify;font-size: 16px;"> <section style="border-bottom: 1px solid black;margin: 0.5em 0px;line-height: 1.2;box-sizing: border-box;"> <section style="display: inline-block;border-color: rgb(89, 89, 89);border-bottom: 6px solid rgb(89, 89, 89);margin-bottom: -1px;font-size: 20px;color: rgb(89, 89, 89);box-sizing: border-box;"> <p style="margin: 0px;padding: 0px;box-sizing: border-box;">代码评审</p> </section> </section> </section> <section style="line-height: normal;"> <br> </section> <h3 data-tool="mdnice编辑器" style="text-align: justify;margin-left: 8px;margin-right: 8px;line-height: 1.75em;"><strong><span style="font-size: 15px;color: rgb(89, 89, 89);letter-spacing: 1px;">①日志规范</span></strong></h3> <p style="line-height: normal;"><br></p> <section style="text-align: justify;margin-left: 8px;margin-right: 8px;line-height: 1.75em;margin-bottom: 5px;"> <span style="font-size: 15px;color: rgb(89, 89, 89);letter-spacing: 1px;">日志是整个代码开发过程中非常重要的环节，如果日志打的不好，那么遇到的线上 Bug 就没法快速定位，定位不了问题也就没法快速解决问题。直接带来的结果可能包括；客诉更多、资损更大、修复更慢。<br></span> </section> <section style="font-size: 16px;color: rgb(62, 62, 62);line-height: 1.6;word-spacing: 0px;letter-spacing: 0px;font-family: &quot;Helvetica Neue&quot;, Helvetica, &quot;Hiragino Sans GB&quot;, &quot;Microsoft YaHei&quot;, Arial, sans-serif;"> <pre style="font-size: inherit;color: inherit;line-height: inherit;margin: 0px;padding: 0px;"><code style="white-space:pre-wrap;overflow-wrap: break-word;margin: 0px 2px;line-height: 18px;font-size: 14px;font-weight: normal;word-spacing: 0px;letter-spacing: 0px;font-family: Consolas, Inconsolata, Courier, monospace;border-radius: 0px;color: rgb(169, 183, 198);background: rgb(40, 43, 46);overflow-x: auto;padding: 0.5em;word-wrap: normal !important;word-break: normal !important;overflow: auto !important;display: -webkit-box !important;"><span style="font-size: inherit;line-height: inherit;margin: 0px;padding: 0px;color: rgb(248, 35, 117);word-wrap: inherit !important;word-break: inherit !important;">public</span>&nbsp;Result&nbsp;execRule(RuleReq&nbsp;req)&nbsp;{<br>&nbsp;&nbsp;&nbsp;&nbsp;<span style="font-size: inherit;line-height: inherit;margin: 0px;padding: 0px;color: rgb(248, 35, 117);word-wrap: inherit !important;word-break: inherit !important;">try</span>&nbsp;{<br>&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;logger.info(<span style="font-size: inherit;line-height: inherit;margin: 0px;padding: 0px;color: rgb(238, 220, 112);word-wrap: inherit !important;word-break: inherit !important;">"执行服务规则 req：{}"</span>,&nbsp;JSON.toJSONString(req));<br>&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;<span style="font-size: inherit;line-height: inherit;margin: 0px;padding: 0px;color: rgb(128, 128, 128);word-wrap: inherit !important;word-break: inherit !important;">//&nbsp;业务流程</span><br>&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;<span style="font-size: inherit;line-height: inherit;margin: 0px;padding: 0px;color: rgb(248, 35, 117);word-wrap: inherit !important;word-break: inherit !important;">return</span>&nbsp;Result.buildSuccess();<br>&nbsp;&nbsp;&nbsp;&nbsp;}&nbsp;<span style="font-size: inherit;line-height: inherit;margin: 0px;padding: 0px;color: rgb(248, 35, 117);word-wrap: inherit !important;word-break: inherit !important;">catch</span>&nbsp;(Exception&nbsp;e)&nbsp;{<br>&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;logger.error(<span style="font-size: inherit;line-height: inherit;margin: 0px;padding: 0px;color: rgb(238, 220, 112);word-wrap: inherit !important;word-break: inherit !important;">"执行服务规则失败"</span>,&nbsp;e);<br>&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;<span style="font-size: inherit;line-height: inherit;margin: 0px;padding: 0px;color: rgb(248, 35, 117);word-wrap: inherit !important;word-break: inherit !important;">return</span>&nbsp;Result.buildError(e);<br>&nbsp;&nbsp;&nbsp;&nbsp;}<br>}<br></code></pre> </section> <section style="line-height: normal;"> <br> </section> <p style="margin-left: 8px;margin-right: 8px;line-height: 1.75em;"><span style="font-size: 15px;letter-spacing: 1px;color: rgb(71, 193, 168);">就像上面这段代码中的日志：</span></p> <ul style="list-style-type: disc;" class="list-paddingleft-2"> <li><p style="text-align: justify;line-height: 1.75em;"><span style="font-size: 15px;color: rgb(89, 89, 89);letter-spacing: 1px;">看似没什么问题，但在这段异常代码中，没有打方法的入参信息。如果方法异常时只是抛出一些异常栈信息，那么是很难定位具体的由次调用触发的。</span></p></li> <li> <section style="text-align: justify;line-height: 1.75em;margin-bottom: 5px;"> <span style="font-size: 15px;color: rgb(89, 89, 89);letter-spacing: 1px;">另外如果你的系统监控服务，没有类似方法跟踪 ID 的功能，最好还需要在日志中把本次调用具有标识性的 id，作为查询条件打到日志中。</span> <br> </section></li> </ul> <section style="font-size: 16px;color: rgb(62, 62, 62);line-height: 1.6;word-spacing: 0px;letter-spacing: 0px;font-family: &quot;Helvetica Neue&quot;, Helvetica, &quot;Hiragino Sans GB&quot;, &quot;Microsoft YaHei&quot;, Arial, sans-serif;"> <pre style="font-size: inherit;color: inherit;line-height: inherit;margin: 0px;padding: 0px;"><code style="white-space:pre-wrap;overflow-wrap: break-word;margin: 0px 2px;line-height: 18px;font-size: 14px;font-weight: normal;word-spacing: 0px;letter-spacing: 0px;font-family: Consolas, Inconsolata, Courier, monospace;border-radius: 0px;color: rgb(169, 183, 198);background: rgb(40, 43, 46);overflow-x: auto;padding: 0.5em;word-wrap: normal !important;word-break: normal !important;overflow: auto !important;display: -webkit-box !important;"><span style="font-size: inherit;line-height: inherit;margin: 0px;padding: 0px;color: rgb(248, 35, 117);word-wrap: inherit !important;word-break: inherit !important;">public</span>&nbsp;Result&nbsp;execRule(RuleReq&nbsp;req)&nbsp;{<br>&nbsp;&nbsp;&nbsp;&nbsp;<span style="font-size: inherit;line-height: inherit;margin: 0px;padding: 0px;color: rgb(248, 35, 117);word-wrap: inherit !important;word-break: inherit !important;">try</span>&nbsp;{<br>&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;logger.info(<span style="font-size: inherit;line-height: inherit;margin: 0px;padding: 0px;color: rgb(238, 220, 112);word-wrap: inherit !important;word-break: inherit !important;">"执行服务规则{}开始 req：{}"</span>,&nbsp;req.getrId(),&nbsp;JSON.toJSONString(req));<br>&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;<span style="font-size: inherit;line-height: inherit;margin: 0px;padding: 0px;color: rgb(128, 128, 128);word-wrap: inherit !important;word-break: inherit !important;">//&nbsp;业务流程</span><br>&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;logger.info(<span style="font-size: inherit;line-height: inherit;margin: 0px;padding: 0px;color: rgb(238, 220, 112);word-wrap: inherit !important;word-break: inherit !important;">"执行服务规则{}完成 res：{}"</span>,&nbsp;req.getrId(),&nbsp;<span style="font-size: inherit;line-height: inherit;margin: 0px;padding: 0px;color: rgb(238, 220, 112);word-wrap: inherit !important;word-break: inherit !important;">"业务流程，必要的结果信息"</span>);<br>&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;<span style="font-size: inherit;line-height: inherit;margin: 0px;padding: 0px;color: rgb(248, 35, 117);word-wrap: inherit !important;word-break: inherit !important;">return</span>&nbsp;Result.buildSuccess();<br>&nbsp;&nbsp;&nbsp;&nbsp;}&nbsp;<span style="font-size: inherit;line-height: inherit;margin: 0px;padding: 0px;color: rgb(248, 35, 117);word-wrap: inherit !important;word-break: inherit !important;">catch</span>&nbsp;(Exception&nbsp;e)&nbsp;{<br>&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;logger.error(<span style="font-size: inherit;line-height: inherit;margin: 0px;padding: 0px;color: rgb(238, 220, 112);word-wrap: inherit !important;word-break: inherit !important;">"执行服务规则{}失败 req：{}"</span>,&nbsp;req.getrId(),&nbsp;JSON.toJSONString(req),&nbsp;e);<br>&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;<span style="font-size: inherit;line-height: inherit;margin: 0px;padding: 0px;color: rgb(248, 35, 117);word-wrap: inherit !important;word-break: inherit !important;">return</span>&nbsp;Result.buildError(e);<br>&nbsp;&nbsp;&nbsp;&nbsp;}<br>}<br></code></pre> </section> <section style="line-height: normal;"> <br> </section> <p style="margin-left: 8px;margin-right: 8px;line-height: 1.75em;"><span style="font-size: 15px;letter-spacing: 1px;color: rgb(71, 193, 168);">修改后的日志如上：</span></p> <ul style="list-style-type: disc;" class="list-paddingleft-2"> <li><p style="text-align: justify;line-height: 1.75em;"><span style="font-size: 15px;color: rgb(89, 89, 89);letter-spacing: 1px;">那么现在这样改成这样打日志，就可以非常方便的查询问题，例如搜索；执行服务规则 100098921，那么它的一整串关于这次调用的信息就可以都搜索出来了，方便排查问题。</span></p></li> <li><p style="text-align: justify;line-height: 1.75em;"><span style="font-size: 15px;color: rgb(89, 89, 89);letter-spacing: 1px;">在异常中打印入参是为了更加方便的定位问题，不需要比对上下文。</span></p></li> <li><p style="text-align: justify;line-height: 1.75em;"><span style="font-size: 15px;color: rgb(89, 89, 89);letter-spacing: 1px;">打日志还有很多技巧，但所有打的日志目的都为了在出问题时可以快速定位问题，但也注意不要打太多日志，精简好用即可。</span></p></li> </ul> <h3 data-tool="mdnice编辑器" style="line-height: normal;"><br></h3> <h3 data-tool="mdnice编辑器" style="text-align: justify;margin-left: 8px;margin-right: 8px;line-height: 1.75em;"><strong><span style="font-size: 15px;color: rgb(89, 89, 89);letter-spacing: 1px;">②IDEA 提示</span></strong></h3> <section style="line-height: normal;"> <br> </section> <p style="text-align: justify;margin-left: 8px;margin-right: 8px;line-height: 1.75em;"><span style="font-size: 15px;color: rgb(89, 89, 89);letter-spacing: 1px;">很多时候因为你，走神、疏忽、手滑，写出来的错误代码，IntelliJ IDEA，都会给你警告⚠提示，只是你，没有去看、没有去看、没有去看！<br></span></p> <section style="line-height: normal;"> <br> </section> <section style="text-align: justify;margin-left: 8px;margin-right: 8px;line-height: 1.75em;margin-bottom: 5px;"> <span style="font-size: 15px;letter-spacing: 1px;color: rgb(71, 193, 168);">来自 idea 的警告：</span> </section> <p style="text-align: center;margin-left: 8px;margin-right: 8px;margin-bottom: 5px;"><img class="rich_pages" data-ratio="0.6662162162162162" data-s="300,640" src="/upload/4d1368e83c3575b9fe748cd8b51f3452.jpg" data-type="jpeg" data-w="740" style=""></p> <p style="text-align: center;margin-left: 8px;margin-right: 8px;line-height: 1.75em;"><span style="font-size: 14px;color: rgb(89, 89, 89);letter-spacing: 1px;"><em>idea 警告</em></span></p> <section style="line-height: normal;"> <br> </section> <section style="text-align: justify;line-height: 1.75em;margin-left: 8px;margin-right: 8px;"> <span style="font-size: 15px;color: rgb(89, 89, 89);letter-spacing: 1px;">idea 在警告提示这方面非常优秀，只要你能看得见，按照它的提示修改，就可以减少很多的错误。如果你还希望有更强的提示，那么你可以按照 p3c 插件，帮你检查代码错误。</span> </section> <h3 data-tool="mdnice编辑器" style="line-height: normal;"><br></h3> <h3 data-tool="mdnice编辑器" style="text-align: justify;margin-left: 8px;margin-right: 8px;line-height: 1.75em;"><strong><span style="font-size: 15px;color: rgb(89, 89, 89);letter-spacing: 1px;">③代码格式</span></strong></h3> <section style="line-height: normal;"> <br> </section> <p style="text-align: justify;margin-left: 8px;margin-right: 8px;line-height: 1.75em;"><span style="font-size: 15px;color: rgb(89, 89, 89);letter-spacing: 1px;">可能这并不是一个致命的问题，但代码格式化最大的好处是，提升可读性、规整性、以及可以让整组人都在一个标准下执行。<br></span></p> <section style="line-height: normal;"> <br> </section> <p style="text-align: justify;margin-left: 8px;margin-right: 8px;line-height: 1.75em;"><span style="font-size: 15px;color: rgb(89, 89, 89);letter-spacing: 1px;">因为很多时候一个组的程序员，会在一个类下开发，有人格式化、有人不格式化除了不好看以外，合并代码有时候也会遇到麻烦。<br></span></p> <section style="line-height: normal;"> <br> </section> <section style="text-align: justify;margin-left: 8px;margin-right: 8px;line-height: 1.75em;margin-bottom: 5px;"> <span style="font-size: 15px;letter-spacing: 1px;color: rgb(71, 193, 168);">不格式化的代码缺少灵魂：</span> </section> <section style="text-align: center;margin-bottom: 5px;"> <img class="rich_pages" data-ratio="0.5590909090909091" data-s="300,640" src="/upload/639e24dbb21b262834525605427a2bc2.jpg" data-type="jpeg" data-w="440" style=""> </section> <figure data-tool="mdnice编辑器"> <p style="text-align: center;margin-left: 8px;margin-right: 8px;line-height: 1.75em;"><span style="color: rgb(89, 89, 89);font-size: 14px;letter-spacing: 1px;"><em>代码格式化</em></span></p> <section style="line-height: normal;"> <br> </section> </figure> <section style="text-align: justify;line-height: 1.75em;margin-left: 8px;margin-right: 8px;"> <span style="font-size: 15px;color: rgb(89, 89, 89);letter-spacing: 1px;">对于严格要自己的程序员来说，代码没有格式化还是很难受的。看一段代码，只要发现差一个空格位置，都知道这是格式化还是没格式化。</span> </section> <h3 data-tool="mdnice编辑器" style="line-height: normal;"><br></h3> <h3 data-tool="mdnice编辑器" style="text-align: justify;margin-left: 8px;margin-right: 8px;line-height: 1.75em;"><strong><span style="font-size: 15px;color: rgb(89, 89, 89);letter-spacing: 1px;">④单元测试</span></strong></h3> <section style="line-height: normal;"> <br> </section> <p style="text-align: justify;margin-left: 8px;margin-right: 8px;line-height: 1.75em;"><span style="font-size: 15px;color: rgb(89, 89, 89);letter-spacing: 1px;">单测？覆盖率？写代码不是写完就可以了吗？<br></span></p> <section style="line-height: normal;"> <br> </section> <p style="text-align: justify;margin-left: 8px;margin-right: 8px;line-height: 1.75em;"><span style="font-size: 15px;color: rgb(89, 89, 89);letter-spacing: 1px;">当然不是，你写的代码你需要保证它能你跑通你所有的流程节点，确保这份功能是没有问题的，才能提交给测试，否则来回反复，耗时耗力。<br></span></p> <section style="line-height: normal;"> <br> </section> <section style="text-align: justify;margin-left: 8px;margin-right: 8px;line-height: 1.75em;margin-bottom: 5px;"> <span style="font-size: 15px;color: rgb(89, 89, 89);letter-spacing: 1px;">这也就是写单测的目的！甚至好一点的研发可以通过单测驱动开发，在这个阶段能把一些共用的方法合并、抽离，避免过多的冗余方法。<br></span> </section> <p style="text-align: center;margin-left: 8px;margin-right: 8px;margin-bottom: 5px;"><img class="rich_pages" data-ratio="0.3787037037037037" data-s="300,640" src="/upload/fc33479f96a0e11ecc38030db8cd97b1.jpg" data-type="jpeg" data-w="1080" style=""></p> <p style="text-align: justify;margin-left: 8px;margin-right: 8px;line-height: 1.75em;"><span style="font-size: 15px;letter-spacing: 1px;color: rgb(71, 193, 168);">单测长什么样，如上图：</span><br></p> <ul style="list-style-type: disc;" class="list-paddingleft-2"> <li><p style="text-align: justify;line-height: 1.75em;"><span style="font-size: 15px;color: rgb(89, 89, 89);letter-spacing: 1px;">单测完整基本也就是代码的健壮性更好，能把单测写好，基本提交的代码就不会有那么多测试妹子找你聊天。</span></p></li> <li><p style="text-align: justify;line-height: 1.75em;"><span style="font-size: 15px;color: rgb(89, 89, 89);letter-spacing: 1px;">在很多公司中一般都会要求单测覆盖率超过多少，否则是不允许编译提交的，这有插件可以和 Jenkins 配合使用。</span></p></li> </ul> <h3 data-tool="mdnice编辑器" style="line-height: normal;"><br></h3> <h3 data-tool="mdnice编辑器" style="text-align: justify;margin-left: 8px;margin-right: 8px;line-height: 1.75em;"><strong><span style="font-size: 15px;color: rgb(89, 89, 89);letter-spacing: 1px;">⑤分支规范</span></strong></h3> <section style="line-height: normal;"> <br> </section> <p style="text-align: justify;margin-left: 8px;margin-right: 8px;line-height: 1.75em;"><span style="font-size: 15px;color: rgb(89, 89, 89);letter-spacing: 1px;">可能有些人看到分支规范根本没有感觉，因为他们开发的项目较小，没有多人开发，上线周期也短，也不会开发中添加需求。<br></span></p> <section style="line-height: normal;"> <br> </section> <p style="text-align: justify;margin-left: 8px;margin-right: 8px;line-height: 1.75em;"><span style="font-size: 15px;color: rgb(89, 89, 89);letter-spacing: 1px;">但在互联网中并不是这样，往往一个系统需要几个人维护，并同时进行开发。一般这里会包括 master 分支、test 分支、本次需求的分支。<br></span></p> <section style="line-height: normal;"> <br> </section> <p style="text-align: justify;margin-left: 8px;margin-right: 8px;line-height: 1.75em;"><span style="font-size: 15px;letter-spacing: 1px;color: rgb(71, 193, 168);">有这么多分支怎么用呢，如下：</span></p> <ul style="list-style-type: disc;" class="list-paddingleft-2"> <li><p style="text-align: justify;line-height: 1.75em;"><strong><span style="font-size: 15px;color: rgb(89, 89, 89);letter-spacing: 1px;">master 分支，</span></strong><span style="font-size: 15px;color: rgb(89, 89, 89);letter-spacing: 1px;">是主分支，也是上线分支，不允许在上面直接修改代码。</span></p></li> <li><p style="text-align: justify;line-height: 1.75em;"><strong><span style="font-size: 15px;color: rgb(89, 89, 89);letter-spacing: 1px;">test 分支，</span></strong><span style="font-size: 15px;color: rgb(89, 89, 89);letter-spacing: 1px;">是测试环境分支，每个人都需要把自己开发完的分支，提测后合并到 test 分支，交由测试验证。</span></p></li> <li><p style="text-align: justify;line-height: 1.75em;"><strong><span style="font-size: 15px;color: rgb(89, 89, 89);letter-spacing: 1px;">需求分支</span></strong><span style="font-size: 15px;color: rgb(89, 89, 89);letter-spacing: 1px;">，也是个人开发的分支，同一个需求下，大家在这个分支写代码，当然也可能这个系统模块的分支就一个人在开发。</span></p></li> </ul> <section style="line-height: normal;"> <br> </section> <p style="text-align: justify;margin-left: 8px;margin-right: 8px;line-height: 1.75em;"><span style="font-size: 15px;color: rgb(89, 89, 89);letter-spacing: 1px;">重点，如果有人不遵守分支规范或者压根没概念，把自己的需求代码写在 test 分支上，并且是多次修改提交都在 test 分支写。那么就危险了，严重会耽误上线。<br></span></p> <section style="line-height: normal;"> <br> </section> <p style="text-align: justify;margin-left: 8px;margin-right: 8px;line-height: 1.75em;"><span style="font-size: 15px;letter-spacing: 1px;color: rgb(71, 193, 168);">为什么？</span></p> <ul style="list-style-type: disc;" class="list-paddingleft-2"> <li><p style="text-align: justify;line-height: 1.75em;"><span style="font-size: 15px;color: rgb(89, 89, 89);letter-spacing: 1px;">test 分支，是由大家把自己的代码合并过来共用的，那么这个分支就会包含 2 个或者更多的并行需求，当你需要上线的时候，需要把自己的代码合并到 master，但 test 分支代码是不能合并到 master 的，那么多未知的内容，根本没有在上线范围。</span></p></li> <li><p style="text-align: justify;line-height: 1.75em;"><span style="font-size: 15px;color: rgb(89, 89, 89);letter-spacing: 1px;">那么你又想上线，又不能避开 test 分支，就需要把你写的代码，重新粘贴过去，这个时间成本非常大。</span></p></li> <li><p style="text-align: justify;line-height: 1.75em;"><span style="font-size: 15px;color: rgb(89, 89, 89);letter-spacing: 1px;">test 分支，还随时有删除重新拉的可能，如果有人通知大家删除重新拉，那你的代码就会丢失。</span></p></li> </ul> <h3 data-tool="mdnice编辑器" style="line-height: normal;"><br></h3> <h3 data-tool="mdnice编辑器" style="text-align: justify;margin-left: 8px;margin-right: 8px;line-height: 1.75em;"><strong><span style="font-size: 15px;color: rgb(89, 89, 89);letter-spacing: 1px;">⑥夹带需求</span></strong></h3> <section style="line-height: normal;"> <br> </section> <span style="font-size: 15px;color: rgb(89, 89, 89);letter-spacing: 1px;"></span> <p style="text-align: justify;margin-left: 8px;margin-right: 8px;line-height: 1.75em;"><strong><span style="font-size: 15px;color: rgb(89, 89, 89);letter-spacing: 1px;">提交测试，但还藏一个需求。<br></span></strong></p> <section style="line-height: normal;"> <br> </section> <p style="text-align: justify;margin-left: 8px;margin-right: 8px;line-height: 1.75em;"><strong><span style="font-size: 15px;color: rgb(89, 89, 89);letter-spacing: 1px;"></span></strong><span style="font-size: 15px;color: rgb(89, 89, 89);letter-spacing: 1px;">研发开发需求代码时候，有时候会额外加一些其他代码，而且这些代码可能跟本次需求并没有关系。<br></span></p> <section style="line-height: normal;"> <br> </section> <p style="text-align: justify;margin-left: 8px;margin-right: 8px;line-height: 1.75em;"><span style="font-size: 15px;letter-spacing: 1px;color: rgb(71, 193, 168);">那为什么会这样呢？</span></p> <ul style="list-style-type: disc;" class="list-paddingleft-2"> <li><p style="text-align: justify;line-height: 1.75em;"><span style="font-size: 15px;color: rgb(89, 89, 89);letter-spacing: 1px;">以前留下来的 Bug，想修复下，但忘记告知测试。</span></p></li> <li><p style="text-align: justify;line-height: 1.75em;"><span style="font-size: 15px;color: rgb(89, 89, 89);letter-spacing: 1px;">在开发这个需求时，其他产品又找过来让加功能，并说功能很小，没有发邮件通知相关测试人员。</span></p></li> <li><p style="text-align: justify;line-height: 1.75em;"><span style="font-size: 15px;color: rgb(89, 89, 89);letter-spacing: 1px;">看到某块以前写的代码太乱了，就想着优化下，自信心很高，不必告诉测试。</span></p></li> </ul> <section style="line-height: normal;"> <br> </section> <p style="text-align: justify;margin-left: 8px;margin-right: 8px;line-height: 1.75em;"><span style="font-size: 15px;color: rgb(89, 89, 89);letter-spacing: 1px;">那这时候你提交的代码，如果不在测试范围又出了问题，只能研发自己抗。并且在所有的研发团队，几乎是不会让夹带需求上线的，这样的做完了不算功劳，做出了问题还会被骂。<br></span></p> <section style="line-height: normal;"> <br> </section> <p style="text-align: justify;margin-left: 8px;margin-right: 8px;line-height: 1.75em;"><span style="font-size: 15px;color: rgb(89, 89, 89);letter-spacing: 1px;">所以，千万不要私自夹带！哪怕你是好心！<br></span></p> <p style="line-height: normal;"><br></p> <h3 data-tool="mdnice编辑器" style="text-align: justify;margin-left: 8px;margin-right: 8px;line-height: 1.75em;"><strong><span style="font-size: 15px;color: rgb(89, 89, 89);letter-spacing: 1px;">⑦异常流程</span></strong></h3> <section style="line-height: normal;"> <br> </section> <p style="text-align: justify;margin-left: 8px;margin-right: 8px;line-height: 1.75em;"><strong><span style="font-size: 15px;color: rgb(89, 89, 89);letter-spacing: 1px;">擦屁屁的纸，80% 的面积都是保护手的！</span></strong><span style="font-size: 15px;color: rgb(89, 89, 89);letter-spacing: 1px;"><br></span></p> <section style="line-height: normal;"> <br> </section> <p style="text-align: justify;margin-left: 8px;margin-right: 8px;line-height: 1.75em;"><span style="font-size: 15px;color: rgb(89, 89, 89);letter-spacing: 1px;">这句话是我经常用的，因为我们编程很多时候都是在处理异常流程，正常流程往往并不难，难的是分析出这段开发的代码有多少异常流程有没有处理。<br></span></p> <section style="line-height: normal;"> <br> </section> <p style="text-align: justify;margin-left: 8px;margin-right: 8px;line-height: 1.75em;"><span style="font-size: 15px;letter-spacing: 1px;color: rgb(71, 193, 168);">那么，会有哪些异常呢？</span></p> <ul style="list-style-type: disc;" class="list-paddingleft-2"> <li><p style="text-align: justify;line-height: 1.75em;"><span style="font-size: 15px;color: rgb(89, 89, 89);letter-spacing: 1px;">支付成功 MQ 消息发送失败，需要 worker 补偿。</span></p></li> <li><p style="text-align: justify;line-height: 1.75em;"><span style="font-size: 15px;color: rgb(89, 89, 89);letter-spacing: 1px;">PRC 接口调用失败，网络超时，实际成功。</span></p></li> <li><p style="text-align: justify;line-height: 1.75em;"><span style="font-size: 15px;color: rgb(89, 89, 89);letter-spacing: 1px;">接口幂等性，多次调用结果一致性。</span></p></li> </ul> <section style="line-height: normal;"> <br> </section> <p style="text-align: justify;margin-left: 8px;margin-right: 8px;line-height: 1.75em;"><span style="font-size: 15px;color: rgb(89, 89, 89);letter-spacing: 1px;">等等，这些都是异常流程，尤其在一些交易提现环节，会出现各种异常，那么不可能把这些异常都反馈用户展示到界面。<br></span></p> <section style="line-height: normal;"> <br> </section> <p style="text-align: justify;margin-left: 8px;margin-right: 8px;line-height: 1.75em;"><span style="font-size: 15px;color: rgb(89, 89, 89);letter-spacing: 1px;">而是要有一些非常友好的提示，并且在服务端的流程里，有一定的补偿机制，来保证最终的调用成功，或者逆反。<br></span></p> <p style="line-height: normal;"><br></p> <h3 data-tool="mdnice编辑器" style="text-align: justify;margin-left: 8px;margin-right: 8px;line-height: 1.75em;"><strong><span style="font-size: 15px;color: rgb(89, 89, 89);letter-spacing: 1px;">⑧代码成坨</span></strong></h3> <p style="line-height: normal;"><br></p> <section style="text-align: center;margin-left: 8px;margin-right: 8px;"> <img class="rich_pages" data-ratio="1.0631443298969072" data-s="300,640" src="/upload/6f821d0b5d0efe8427e71bfcadfee93.jpg" data-type="jpeg" data-w="776" style=""> </section> <section style="text-align: center;line-height: 1.75em;"> <span style="font-size: 14px;color: rgb(89, 89, 89);letter-spacing: 1px;"><em>代码成坨</em></span> <br> </section> <section style="line-height: normal;"> <br> </section> <figure data-tool="mdnice编辑器"></figure> <p style="text-align: justify;margin-left: 8px;margin-right: 8px;line-height: 1.75em;"><strong><span style="font-size: 15px;color: rgb(89, 89, 89);letter-spacing: 1px;">CRUD 往往可能是因为你的设计，换个人写也许不同。<br></span></strong></p> <section style="line-height: normal;"> <br> </section> <p style="text-align: justify;margin-left: 8px;margin-right: 8px;line-height: 1.75em;"><strong><span style="font-size: 15px;color: rgb(89, 89, 89);letter-spacing: 1px;"></span></strong><span style="font-size: 15px;color: rgb(89, 89, 89);letter-spacing: 1px;">很多时候研发写代码，根本不考虑是否要扩展，总之一个类+几十行 if else，能搞定所有需求。等下次在开发类似的，就粘贴过去再修修补补，能用就行。<br></span></p> <section style="line-height: normal;"> <br> </section> <p style="text-align: justify;margin-left: 8px;margin-right: 8px;line-height: 1.75em;"><span style="font-size: 15px;color: rgb(89, 89, 89);letter-spacing: 1px;">缺少写出良好代码的研发，一方面是经历有限，另外一方面是学了很多理论但是不好落地。比如设计模式，但自己实际写代码的时候还是很晕。<br></span></p> <p style="line-height: normal;"><br></p> <h3 data-tool="mdnice编辑器" style="text-align: justify;margin-left: 8px;margin-right: 8px;line-height: 1.75em;"><strong><span style="font-size: 15px;color: rgb(89, 89, 89);letter-spacing: 1px;">⑨SQL 性能</span></strong></h3> <section style="line-height: normal;"> <br> </section> <section style="font-size: 16px;color: rgb(62, 62, 62);line-height: 1.6;word-spacing: 0px;letter-spacing: 0px;font-family: &quot;Helvetica Neue&quot;, Helvetica, &quot;Hiragino Sans GB&quot;, &quot;Microsoft YaHei&quot;, Arial, sans-serif;"> <pre style="font-size: inherit;color: inherit;line-height: inherit;margin: 0px;padding: 0px;"><code style="white-space:pre-wrap;overflow-wrap: break-word;margin: 0px 2px;line-height: 18px;font-size: 14px;font-weight: normal;word-spacing: 0px;letter-spacing: 0px;font-family: Consolas, Inconsolata, Courier, monospace;border-radius: 0px;color: rgb(169, 183, 198);background: rgb(40, 43, 46);overflow-x: auto;padding: 0.5em;word-wrap: normal !important;word-break: normal !important;overflow: auto !important;display: -webkit-box !important;"><span style="font-size: inherit;line-height: inherit;margin: 0px;padding: 0px;color: rgb(248, 35, 117);word-wrap: inherit !important;word-break: inherit !important;">select</span>&nbsp;*&nbsp;<span style="font-size: inherit;line-height: inherit;margin: 0px;padding: 0px;color: rgb(248, 35, 117);word-wrap: inherit !important;word-break: inherit !important;">from</span>&nbsp;<span style="font-size: inherit;line-height: inherit;margin: 0px;padding: 0px;color: rgb(248, 35, 117);word-wrap: inherit !important;word-break: inherit !important;">table</span>&nbsp;<span style="font-size: inherit;line-height: inherit;margin: 0px;padding: 0px;color: rgb(248, 35, 117);word-wrap: inherit !important;word-break: inherit !important;">where</span>&nbsp;<span style="font-size: inherit;line-height: inherit;margin: 0px;padding: 0px;color: rgb(248, 35, 117);word-wrap: inherit !important;word-break: inherit !important;">status</span>&nbsp;=&nbsp;<span style="font-size: inherit;line-height: inherit;margin: 0px;padding: 0px;color: rgb(174, 135, 250);word-wrap: inherit !important;word-break: inherit !important;">1</span>&nbsp;<span style="font-size: inherit;line-height: inherit;margin: 0px;padding: 0px;color: rgb(248, 35, 117);word-wrap: inherit !important;word-break: inherit !important;">limit</span>&nbsp;<span style="font-size: inherit;line-height: inherit;margin: 0px;padding: 0px;color: rgb(174, 135, 250);word-wrap: inherit !important;word-break: inherit !important;">200</span>;<br></code></pre> </section> <p style="line-height: normal;"><br></p> <p style="text-align: justify;margin-left: 8px;margin-right: 8px;line-height: 1.75em;"><span style="font-size: 15px;color: rgb(89, 89, 89);letter-spacing: 1px;">这是一段定时任务扫描库表的 SQL，这段 SQL 会定时扫库，将库表中状态是 1 的扫描出来进行处理，每次扫描 200 行。<br></span></p> <section style="line-height: normal;"> <br> </section> <p style="text-align: justify;margin-left: 8px;margin-right: 8px;line-height: 1.75em;"><span style="font-size: 15px;letter-spacing: 1px;color: rgb(71, 193, 168);">你发现有什么问题了吗？</span></p> <ul style="list-style-type: disc;" class="list-paddingleft-2"> <li><p style="text-align: justify;line-height: 1.75em;"><span style="font-size: 15px;color: rgb(89, 89, 89);letter-spacing: 1px;">扫描必要字段即可，不需要全部字段。</span></p></li> <li><p style="text-align: justify;line-height: 1.75em;"><span style="font-size: 15px;color: rgb(89, 89, 89);letter-spacing: 1px;">这段 SQL 会越来越慢，即使状态字段加了索引。因为 status 并不能大量排掉其他状态字段，随着数据越来越多依然是全表扫描。</span></p></li> </ul> <section style="line-height: normal;"> <br> </section> <p style="text-align: justify;margin-left: 8px;margin-right: 8px;line-height: 1.75em;"><span style="font-size: 15px;color: rgb(89, 89, 89);letter-spacing: 1px;">那么怎么优化呢，其实优化也比较简单，需要先根据状态查询到符合条件的最小的 id，之后再 SQL 的查询条件中添加 id&gt;xx，即可。<br></span></p> <section style="line-height: normal;"> <br> </section> <section style="text-align: justify;margin-left: 8px;margin-right: 8px;line-height: 1.75em;margin-bottom: 5px;"> <span style="font-size: 15px;color: rgb(89, 89, 89);letter-spacing: 1px;">另外如果你的任务需要多个 worker 扫描，增加效率，可以增加门牌号设计，提升扫描效率，如下：<br></span> </section> <section style="text-align: center;margin-left: 8px;margin-right: 8px;"> <img class="rich_pages" data-ratio="0.6851063829787234" data-s="300,640" src="/upload/ebf0e70c03713ca9f5888de061ba2f51.jpg" data-type="jpeg" data-w="940" style=""> </section> <p style="text-align: center;margin-left: 8px;margin-right: 8px;line-height: 1.75em;"><span style="font-size: 14px;letter-spacing: 1px;"><em><span style="font-size: 14px;color: rgb(89, 89, 89);letter-spacing: 1px;">门牌号扫描</span></em></span></p> <figure data-tool="mdnice编辑器"></figure> <h3 data-tool="mdnice编辑器" style="line-height: normal;"><br></h3> <h3 data-tool="mdnice编辑器" style="text-align: justify;margin-left: 8px;margin-right: 8px;line-height: 1.75em;"><strong><span style="font-size: 15px;color: rgb(89, 89, 89);letter-spacing: 1px;">⑩结伴编程</span></strong></h3> <p style="line-height: normal;"><br></p> <p style="text-align: justify;margin-left: 8px;margin-right: 8px;line-height: 1.75em;"><span style="font-size: 15px;color: rgb(89, 89, 89);letter-spacing: 1px;">评审代码最后这点想说说，陪伴式开发，可能这不是结伴编程，不是共同合作，而是一个研发需要另外一个研发不断的提供帮助。有时候可能就是很简单的问题，也不想查，或者说没有意识去查，只是问。<br></span></p> <section style="line-height: normal;"> <br> </section> <p style="text-align: justify;margin-left: 8px;margin-right: 8px;line-height: 1.75em;"><span style="font-size: 15px;color: rgb(89, 89, 89);letter-spacing: 1px;">业务开发的过程，只要把流程定下来，研发设计评审完，其他的开发过程中遇到的小点并不难，只要查一查就可以搞定。<br></span></p> <section style="line-height: normal;"> <br> </section> <p style="text-align: justify;margin-left: 8px;margin-right: 8px;line-height: 1.75em;"><span style="font-size: 15px;color: rgb(89, 89, 89);letter-spacing: 1px;">当日也不是说完全不能问，只不过特别普遍，简单的代码问题，自己搞定就可以了，但这个时候还像保姆似的陪伴，就会拖累整个团队的进展，最终大家都需要扛起那个慢的。<br></span></p> <section style="line-height: normal;"> <br> </section> <p style="text-align: justify;margin-left: 8px;margin-right: 8px;line-height: 1.75em;"><span style="font-size: 15px;color: rgb(89, 89, 89);letter-spacing: 1px;">所以，如果你是那个需要陪伴的，要及早断奶，学会自己攻克，快速成长。而如果你是那个卷纸，可哪擦屁股的，要把卷纸传递给他。一个人擦一次是能力体现，反反复复擦一个人，就惹屎上身了。</span><br></p> <section style="line-height: normal;"> <br> </section> <section style="box-sizing: border-box;font-style: normal;font-weight: 400;text-align: justify;font-size: 16px;"> <section style="border-bottom: 1px solid black;margin: 0.5em 0px;line-height: 1.2;box-sizing: border-box;"> <section style="display: inline-block;border-color: rgb(89, 89, 89);border-bottom: 6px solid rgb(89, 89, 89);margin-bottom: -1px;font-size: 20px;color: rgb(89, 89, 89);box-sizing: border-box;"> <p style="margin: 0px;padding: 0px;box-sizing: border-box;">总结</p> </section> </section> </section> <section style="line-height: normal;"> <br> </section> <p style="text-align: justify;margin-left: 8px;margin-right: 8px;line-height: 1.75em;"><span style="font-size: 15px;letter-spacing: 0.5px;color: rgb(71, 193, 168);">总结如下：</span><br></p> <ul style="list-style-type: disc;" class="list-paddingleft-2"> <li><p style="text-align: justify;line-height: 1.75em;"><span style="font-size: 15px;color: rgb(89, 89, 89);letter-spacing: 1px;">以上介绍了代码评审中涉及到的比较常见的点，基本也是很多研发容易忽略和犯错误的地方。这些问题点拿出哪一个看，都不大，但运行在代码中，确都有可能发生致命或者麻烦的事情。</span></p></li> <li><p style="text-align: justify;line-height: 1.75em;"><span style="font-size: 15px;color: rgb(89, 89, 89);letter-spacing: 1px;">想让自己能把代码写好，就不只面试时候造飞机的回答，什么时间复杂度、什么可重入锁、什么红黑树，什么 DDD，只要你不能正确的落地和运用这些技术，说的再多都是空谈。</span></p></li> <li><p style="text-align: justify;line-height: 1.75em;"><span style="font-size: 15px;color: rgb(89, 89, 89);letter-spacing: 1px;">多学一些、多看一些、多问一些，没有坏处，但要自己能成长，把吸取到的经验心得，运用到业务开发中，写出可扩展、可维护的代码，才能让自己真的升职加薪。也能让既有留下的本事，也有出去的能力。</span></p></li> </ul> <section style="line-height: normal;"> <br> </section> <p style="white-space: normal;max-width: 100%;min-height: 1em;font-family: -apple-system-font, BlinkMacSystemFont, &quot;Helvetica Neue&quot;, &quot;PingFang SC&quot;, &quot;Hiragino Sans GB&quot;, &quot;Microsoft YaHei UI&quot;, &quot;Microsoft YaHei&quot;, Arial, sans-serif;letter-spacing: 0.544px;background-color: rgb(255, 255, 255);line-height: 1.75em;box-sizing: border-box !important;overflow-wrap: break-word !important;"><span style="max-width: 100%;color: rgb(89, 89, 89);letter-spacing: 1px;box-sizing: border-box !important;word-wrap: break-word !important;"><em style="max-width: 100%;box-sizing: border-box !important;word-wrap: break-word !important;"><span style="max-width: 100%;font-size: 14px;box-sizing: border-box !important;word-wrap: break-word !important;">作者：</span></em><em style="max-width: 100%;box-sizing: border-box !important;word-wrap: break-word !important;"><span style="max-width: 100%;font-size: 14px;box-sizing: border-box !important;word-wrap: break-word !important;">小傅哥</span></em></span></p> <p style="white-space: normal;max-width: 100%;min-height: 1em;font-family: -apple-system-font, BlinkMacSystemFont, &quot;Helvetica Neue&quot;, &quot;PingFang SC&quot;, &quot;Hiragino Sans GB&quot;, &quot;Microsoft YaHei UI&quot;, &quot;Microsoft YaHei&quot;, Arial, sans-serif;letter-spacing: 0.544px;background-color: rgb(255, 255, 255);line-height: 1.75em;box-sizing: border-box !important;overflow-wrap: break-word !important;"><span style="max-width: 100%;color: rgb(89, 89, 89);letter-spacing: 1px;box-sizing: border-box !important;word-wrap: break-word !important;"><em style="max-width: 100%;box-sizing: border-box !important;word-wrap: break-word !important;"><span style="max-width: 100%;font-size: 14px;box-sizing: border-box !important;word-wrap: break-word !important;">简介：多年从事一线互联网 Java 开发，从 19 年开始编写工作和学习历程的技术汇总，旨在为大家提供一个较清晰详细的核心技能学习文档。</span></em></span></p> <p style="white-space: normal;max-width: 100%;min-height: 1em;font-family: -apple-system-font, BlinkMacSystemFont, &quot;Helvetica Neue&quot;, &quot;PingFang SC&quot;, &quot;Hiragino Sans GB&quot;, &quot;Microsoft YaHei UI&quot;, &quot;Microsoft YaHei&quot;, Arial, sans-serif;letter-spacing: 0.544px;background-color: rgb(255, 255, 255);line-height: 1.75em;box-sizing: border-box !important;overflow-wrap: break-word !important;"><span style="max-width: 100%;color: rgb(89, 89, 89);letter-spacing: 1px;box-sizing: border-box !important;word-wrap: break-word !important;"><em style="max-width: 100%;box-sizing: border-box !important;word-wrap: break-word !important;"><span style="max-width: 100%;font-size: 14px;box-sizing: border-box !important;word-wrap: break-word !important;">编辑：陶家龙</span></em></span><br style="max-width: 100%;box-sizing: border-box !important;word-wrap: break-word !important;"></p> <p><em style="max-width: 100%;box-sizing: border-box !important;word-wrap: break-word !important;"><span style="max-width: 100%;line-height: 1.75em;font-size: 14px;color: rgb(89, 89, 89);letter-spacing: 1px;box-sizing: border-box !important;word-wrap: break-word !important;">出处：转载自公众号 bugstack 虫洞栈（ID：bugstack）<br></span></em></p> <p style="text-align: 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<section data-mpa-powered-by="yiban.io"> <span style="color: rgb(255, 76, 0);font-size: 16px;letter-spacing: 1px;background-color: rgb(255, 255, 255);font-family: Roboto, sans-serif;font-weight: 600;">&gt;&gt; 面试常问问题一</span> </section> <section data-tools="135编辑器" data-id="97272"> <section> <section> <section data-role="outer" label="Powered by 365editor" style="font-family: 微软雅黑;font-size: 16px;"> <blockquote class="js_blockquote_wrap" data-type="2" data-url="" data-author-name="" data-content-utf8-length="76" data-source-title=""> <section class="js_blockquote_digest"> <section> <strong>redis 集群模式的工作原理能说一下么？在集群模式下， redis 的 key 是如何寻址的？分布式寻址都有哪些算法？了解一致性 hash 算法吗？</strong> </section> </section> </blockquote> <p><br></p> <section style="box-sizing: border-box;color: rgb(36, 41, 46);font-family: Roboto, sans-serif;font-size: 14px;text-align: justify;white-space: normal;background-color: rgb(255, 255, 255);margin-top: 20px;margin-bottom: 20px;line-height: 1.75em;"> <span style="box-sizing: border-box;font-weight: bolder;letter-spacing: 1px;font-size: 15px;color: rgb(255, 76, 65);">1、面试官心理分析</span> <br> </section> <section style="box-sizing: border-box;color: rgb(36, 41, 46);font-family: Roboto, sans-serif;font-size: 14px;text-align: justify;white-space: normal;background-color: rgb(255, 255, 255);margin-top: 20px;margin-bottom: 20px;line-height: 1.75em;"> <span style="letter-spacing: 1px;font-size: 15px;">在前几年，redis 如果要搞几个节点，每个节点存储一部分的数据，得借助一些中间件来实现，比如说有codis，或者 twemproxy，都有。有一些 redis 中间件，你读写 redis 中间件，redis 中间件负责将你的数据分布式存储在多台机器上的 redis 实例中。</span> </section> <section style="box-sizing: border-box;color: rgb(36, 41, 46);font-family: Roboto, sans-serif;font-size: 14px;text-align: justify;white-space: normal;background-color: rgb(255, 255, 255);margin-top: 20px;margin-bottom: 20px;line-height: 1.75em;"> <span style="letter-spacing: 1px;font-size: 15px;">这两年，redis 不断在发展，redis 也不断有新的版本，现在的 redis 集群模式，可以做到在多台机器上，部署多个 redis 实例，每个实例存储一部分的数据，同时每个 redis 主实例可以挂 redis 从实例，自动确保说，如果 redis 主实例挂了，会自动切换到 redis 从实例上来。</span> </section> <section style="box-sizing: border-box;color: rgb(36, 41, 46);font-family: Roboto, sans-serif;font-size: 14px;text-align: justify;white-space: normal;background-color: rgb(255, 255, 255);margin-top: 20px;margin-bottom: 20px;line-height: 1.75em;"> <span style="letter-spacing: 1px;font-size: 15px;">现在 redis 的新版本，大家都是用 redis cluster 的，也就是 redis 原生支持的 redis 集群模式，那么面试官肯定会就 redis cluster 对你来个几连炮。要是你没用过 redis cluster，正常，以前很多人用 codis 之类的客户端来支持集群，但是起码你得研究一下 redis cluster 吧。</span> </section> <section style="box-sizing: border-box;color: rgb(36, 41, 46);font-family: Roboto, sans-serif;font-size: 14px;text-align: justify;white-space: normal;background-color: rgb(255, 255, 255);margin-top: 20px;margin-bottom: 20px;line-height: 1.75em;"> <span style="letter-spacing: 1px;font-size: 15px;">如果你的数据量很少，主要是承载高并发高性能的场景，比如你的缓存一般就几个 G，单机就足够了，可以使用 replication，一个 master 多个 slaves，要几个 slave 跟你要求的读吞吐量有关，然后自己搭建一个 sentinel 集群去保证 redis 主从架构的高可用性。</span> </section> <section style="box-sizing: border-box;color: rgb(36, 41, 46);font-family: Roboto, sans-serif;font-size: 14px;text-align: justify;white-space: normal;background-color: rgb(255, 255, 255);margin-top: 20px;margin-bottom: 20px;line-height: 1.75em;"> <span style="letter-spacing: 1px;font-size: 15px;">redis cluster，主要是针对海量数据+高并发+高可用的场景。redis cluster支撑N个 redis master node，每个master node都可以挂载多个slave node。这样整个redis就可以横向扩容了。如果你要支撑更大数据量的缓存，那就横向扩容更多的master节点，每个master节点就能存放更多的数据了。</span> </section> <section style="box-sizing: border-box;color: rgb(36, 41, 46);font-family: Roboto, sans-serif;font-size: 14px;text-align: justify;white-space: normal;background-color: rgb(255, 255, 255);margin-top: 20px;margin-bottom: 20px;line-height: 1.75em;"> <span style="color: rgb(255, 76, 65);font-size: 15px;font-weight: bolder;letter-spacing: 1px;">2、面试题剖析</span> <br> </section> <section style="box-sizing: border-box;color: rgb(36, 41, 46);font-family: Roboto, sans-serif;font-size: 14px;text-align: justify;white-space: normal;background-color: rgb(255, 255, 255);margin-top: 20px;margin-bottom: 20px;line-height: 1.75em;"> <span style="letter-spacing: 1px;font-size: 15px;">redis cluster 介绍</span> </section> <ul style="margin-bottom: 16px;padding-left: 2em;color: rgb(36, 41, 46);font-family: Roboto, sans-serif;font-size: 14px;text-align: left;white-space: normal;background-color: rgb(255, 255, 255);" class="list-paddingleft-2"> <li style="box-sizing: border-box;letter-spacing: 1px;font-size: 15px;"> <section style="text-align: justify;margin-top: 20px;margin-bottom: 20px;line-height: 1.75em;"> <span style="letter-spacing: 1px;font-size: 15px;">自动将数据进行分片，每个 master 上放一部分数据</span> </section></li> <li style="box-sizing: border-box;margin-top: 0.25em;letter-spacing: 1px;font-size: 15px;"> <section style="text-align: justify;margin-top: 20px;margin-bottom: 20px;line-height: 1.75em;"> <span style="letter-spacing: 1px;font-size: 15px;">提供内置的高可用支持，部分 master 不可用时，还是可以继续工作的</span> </section></li> </ul> <section style="box-sizing: border-box;color: rgb(36, 41, 46);font-family: Roboto, sans-serif;font-size: 14px;text-align: justify;white-space: normal;background-color: rgb(255, 255, 255);margin-top: 20px;margin-bottom: 20px;line-height: 1.75em;"> <span style="letter-spacing: 1px;font-size: 15px;">在 redis cluster 架构下，每个 redis 要放开两个端口号，比如一个是 6379，另外一个就是 加 1w 的端口号，比如 16379。</span> </section> <section style="box-sizing: border-box;color: rgb(36, 41, 46);font-family: Roboto, sans-serif;font-size: 14px;text-align: justify;white-space: normal;background-color: rgb(255, 255, 255);margin-top: 20px;margin-bottom: 20px;line-height: 1.75em;"> <span style="letter-spacing: 1px;font-size: 15px;">16379 端口号是用来进行节点间通信的，也就是 cluster bus 的东西，cluster bus 的通信，用来进行故障检测、配置更新、故障转移授权。cluster bus 用了另外一种二进制的协议，gossip 协议，用于节点间进行高效的数据交换，占用更少的网络带宽和处理时间。</span> </section> <section style="box-sizing: border-box;color: rgb(36, 41, 46);font-family: Roboto, sans-serif;font-size: 14px;text-align: justify;white-space: normal;background-color: rgb(255, 255, 255);margin-top: 20px;margin-bottom: 20px;line-height: 1.75em;"> <span style="box-sizing: border-box;font-weight: bolder;letter-spacing: 1px;font-size: 15px;color: rgb(255, 76, 65);">3、节点间的内部通信机制</span> </section> <section style="box-sizing: border-box;color: rgb(36, 41, 46);font-family: Roboto, sans-serif;font-size: 14px;text-align: justify;white-space: normal;background-color: rgb(255, 255, 255);margin-top: 20px;margin-bottom: 20px;line-height: 1.75em;"> <span style="box-sizing: border-box;font-weight: bolder;letter-spacing: 1px;font-size: 15px;">1）基本通信原理</span> </section> <section style="box-sizing: border-box;color: rgb(36, 41, 46);font-family: Roboto, sans-serif;font-size: 14px;text-align: justify;white-space: normal;background-color: rgb(255, 255, 255);margin-top: 20px;margin-bottom: 20px;line-height: 1.75em;"> <span style="letter-spacing: 1px;font-size: 15px;">集群元数据的维护有两种方式：集中式、Gossip 协议。redis cluster 节点间采用 gossip 协议进行通信。</span> </section> <section style="box-sizing: border-box;color: rgb(36, 41, 46);font-family: Roboto, sans-serif;font-size: 14px;text-align: justify;white-space: normal;background-color: rgb(255, 255, 255);margin-top: 20px;margin-bottom: 20px;line-height: 1.75em;"> <span style="letter-spacing: 1px;font-size: 15px;">集中式是将集群元数据（节点信息、故障等等）几种存储在某个节点上。集中式元数据集中存储的一个典型代表，就是大数据领域的 storm。它是分布式的大数据实时计算引擎，是集中式的元数据存储的结构，底层基于 zookeeper（分布式协调的中间件）对所有元数据进行存储维护。</span> </section> <p style="box-sizing: border-box;margin-bottom: 16px;color: rgb(36, 41, 46);font-family: Roboto, sans-serif;font-size: 14px;text-align: left;white-space: normal;background-color: rgb(255, 255, 255);"><img src="/upload/b9a257e2c0aae5521c5fdc192b005ca4.png" data-type="png" style="box-sizing: content-box;vertical-align: middle;border-style: none;display: block;margin: 20px auto;border-radius: 0px 0px 5px 5px;object-fit: contain;box-shadow: rgb(132, 161, 168) 0px 5px 5px;" data-ratio="0.5407554671968191" data-w="503"></p> <section style="box-sizing: border-box;color: rgb(36, 41, 46);font-family: Roboto, sans-serif;font-size: 14px;text-align: justify;white-space: normal;background-color: rgb(255, 255, 255);margin-top: 20px;margin-bottom: 20px;line-height: 1.75em;"> <span style="letter-spacing: 1px;font-size: 15px;">redis 维护集群元数据采用另一个方式， gossip 协议，所有节点都持有一份元数据，不同的节点如果出现了元数据的变更，就不断将元数据发送给其它的节点，让其它节点也进行元数据的变更。</span> </section> <p style="box-sizing: border-box;margin-bottom: 16px;color: rgb(36, 41, 46);font-family: Roboto, sans-serif;font-size: 14px;text-align: left;white-space: normal;background-color: rgb(255, 255, 255);"><img src="/upload/ec88359786508d9738b94e57ef08c1d8.png" data-type="png" style="box-sizing: content-box;vertical-align: middle;border-style: none;display: block;margin: 20px auto;border-radius: 0px 0px 5px 5px;object-fit: contain;box-shadow: rgb(132, 161, 168) 0px 5px 5px;" data-ratio="0.7228381374722838" data-w="451"></p> <section style="box-sizing: border-box;color: rgb(36, 41, 46);font-family: Roboto, sans-serif;font-size: 14px;text-align: justify;white-space: normal;background-color: rgb(255, 255, 255);margin-top: 20px;margin-bottom: 20px;line-height: 1.75em;"> <span style="letter-spacing: 1px;font-size: 15px;">集中式的好处在于，元数据的读取和更新，时效性非常好，一旦元数据出现了变更，就立即更新到集中式的存储中，其它节点读取的时候就可以感知到；不好在于，所有的元数据的更新压力全部集中在一个地方，可能会导致元数据的存储有压力。</span> </section> <section style="box-sizing: border-box;color: rgb(36, 41, 46);font-family: Roboto, sans-serif;font-size: 14px;text-align: justify;white-space: normal;background-color: rgb(255, 255, 255);margin-top: 20px;margin-bottom: 20px;line-height: 1.75em;"> <span style="letter-spacing: 1px;font-size: 15px;">gossip 好处在于，元数据的更新比较分散，不是集中在一个地方，更新请求会陆陆续续打到所有节点上去更新，降低了压力；不好在于，元数据的更新有延时，可能导致集群中的一些操作会有一些滞后。</span> </section> <section style="box-sizing: border-box;color: rgb(36, 41, 46);font-family: Roboto, sans-serif;font-size: 14px;text-align: justify;white-space: normal;background-color: rgb(255, 255, 255);margin-top: 20px;margin-bottom: 20px;line-height: 1.75em;"> <span style="letter-spacing: 1px;font-size: 15px;">10000 端口：每个节点都有一个专门用于节点间通信的端口，就是自己提供服务的端口号+10000，比如7001，那么用于节点间通信的就是 17001 端口。每个节点每隔一段时间都会往另外几个节点发送 ping 消息，同时其它几个节点接收到 ping 之后返回 pong。交换的信息：信息包括故障信息，节点的增加和删除，hash slot 信息等等。</span> </section> <section style="box-sizing: border-box;color: rgb(36, 41, 46);font-family: Roboto, sans-serif;font-size: 14px;text-align: justify;white-space: normal;background-color: rgb(255, 255, 255);margin-top: 20px;margin-bottom: 20px;line-height: 1.75em;"> <span style="box-sizing: border-box;font-weight: bolder;letter-spacing: 1px;font-size: 15px;">2）gossip 协议</span> </section> <section style="box-sizing: border-box;color: rgb(36, 41, 46);font-family: Roboto, sans-serif;font-size: 14px;text-align: justify;white-space: normal;background-color: rgb(255, 255, 255);margin-top: 20px;margin-bottom: 20px;line-height: 1.75em;"> <span style="letter-spacing: 1px;font-size: 15px;">gossip 协议包含多种消息，包含 ping、pong、meet、fail 等等。</span> </section> <section style="box-sizing: border-box;color: rgb(36, 41, 46);font-family: Roboto, sans-serif;font-size: 14px;text-align: justify;white-space: normal;background-color: rgb(255, 255, 255);margin-top: 20px;margin-bottom: 20px;line-height: 1.75em;"> <span style="letter-spacing: 1px;font-size: 15px;"><span style="letter-spacing: 1px;box-sizing: border-box;font-weight: bolder;">meet：</span>某个节点发送 meet 给新加入的节点，让新节点加入集群中，然后新节点就会开始与其它节点进行通信。</span> </section> <section style="box-sizing: border-box;color: rgb(36, 41, 46);font-family: Roboto, sans-serif;font-size: 14px;text-align: justify;white-space: normal;background-color: rgb(255, 255, 255);margin-top: 20px;margin-bottom: 20px;line-height: 1.75em;"> <span style="letter-spacing: 1px;font-size: 15px;">redis-trib.rb add-node</span> </section> <section style="box-sizing: border-box;color: rgb(36, 41, 46);font-family: Roboto, sans-serif;font-size: 14px;text-align: justify;white-space: normal;background-color: rgb(255, 255, 255);margin-top: 20px;margin-bottom: 20px;line-height: 1.75em;"> <span style="letter-spacing: 1px;font-size: 15px;">其实内部就是发送了一个 gossip meet 消息给新加入的节点，通知那个节点去加入我们的集群。</span> </section> <section style="box-sizing: border-box;color: rgb(36, 41, 46);font-family: Roboto, sans-serif;font-size: 14px;text-align: justify;white-space: normal;background-color: rgb(255, 255, 255);margin-top: 20px;margin-bottom: 20px;line-height: 1.75em;"> <span style="letter-spacing: 1px;font-size: 15px;"><span style="letter-spacing: 1px;box-sizing: border-box;font-weight: bolder;">ping：</span>每个节点都会频繁给其它节点发送 ping，其中包含自己的状态还有自己维护的集群元数据，互相通过 ping 交换元数据。</span> </section> <section style="box-sizing: border-box;color: rgb(36, 41, 46);font-family: Roboto, sans-serif;font-size: 14px;text-align: justify;white-space: normal;background-color: rgb(255, 255, 255);margin-top: 20px;margin-bottom: 20px;line-height: 1.75em;"> <span style="letter-spacing: 1px;font-size: 15px;"><span style="letter-spacing: 1px;box-sizing: border-box;font-weight: bolder;">pong：</span>返回ping和meeet，包括自己的状态和其他信息，也用于信息广播和更新。fail：某个节点判断另一个节点fail之后，就发送fail给其他节点，通知其他节点说，某个节点宕机啦。</span> </section> <section style="box-sizing: border-box;color: rgb(36, 41, 46);font-family: Roboto, sans-serif;font-size: 14px;text-align: justify;white-space: normal;background-color: rgb(255, 255, 255);margin-top: 20px;margin-bottom: 20px;line-height: 1.75em;"> <span style="box-sizing: border-box;font-weight: bolder;letter-spacing: 1px;font-size: 15px;">3）ping 消息深入</span> </section> <section style="box-sizing: border-box;color: rgb(36, 41, 46);font-family: Roboto, sans-serif;font-size: 14px;text-align: justify;white-space: normal;background-color: rgb(255, 255, 255);margin-top: 20px;margin-bottom: 20px;line-height: 1.75em;"> <span style="letter-spacing: 1px;font-size: 15px;">ping 时要携带一些元数据，如果很频繁，可能会加重网络负担。</span> </section> <section style="box-sizing: border-box;color: rgb(36, 41, 46);font-family: Roboto, sans-serif;font-size: 14px;text-align: justify;white-space: normal;background-color: rgb(255, 255, 255);margin-top: 20px;margin-bottom: 20px;line-height: 1.75em;"> <span style="letter-spacing: 1px;font-size: 15px;">每个节点每秒会执行 10 次 ping，每次会选择 5 个最久没有通信的其它节点。当然如果发现某个节点通信延时达到了 cluster_node_timeout / 2，那么立即发送 ping，避免数据交换延时过长，落后的时间太长了。</span> </section> <section style="box-sizing: border-box;color: rgb(36, 41, 46);font-family: Roboto, sans-serif;font-size: 14px;text-align: justify;white-space: normal;background-color: rgb(255, 255, 255);margin-top: 20px;margin-bottom: 20px;line-height: 1.75em;"> <span style="letter-spacing: 1px;font-size: 15px;">比如说，两个节点之间都 10 分钟没有交换数据了，那么整个集群处于严重的元数据不一致的情况，就会有问题。所以 cluster_node_timeout 可以调节，如果调得比较大，那么会降低 ping 的频率。</span> </section> <section style="box-sizing: border-box;color: rgb(36, 41, 46);font-family: Roboto, sans-serif;font-size: 14px;text-align: justify;white-space: normal;background-color: rgb(255, 255, 255);margin-top: 20px;margin-bottom: 20px;line-height: 1.75em;"> <span style="letter-spacing: 1px;font-size: 15px;">每次 ping，会带上自己节点的信息，还有就是带上 1/10 其它节点的信息，发送出去，进行交换。至少包含 3 个其它节点的信息，最多包含 总节点数减 2 个其它节点的信息。</span> </section> <section style="box-sizing: border-box;color: rgb(36, 41, 46);font-family: Roboto, sans-serif;font-size: 14px;text-align: justify;white-space: normal;background-color: rgb(255, 255, 255);margin-top: 20px;margin-bottom: 20px;line-height: 1.75em;"> <span style="box-sizing: border-box;font-weight: bolder;letter-spacing: 1px;font-size: 15px;">4）分布式寻址算法</span> </section> <section style="box-sizing: border-box;color: rgb(36, 41, 46);font-family: Roboto, sans-serif;font-size: 14px;text-align: justify;white-space: normal;background-color: rgb(255, 255, 255);margin-top: 20px;margin-bottom: 20px;line-height: 1.75em;"> <span style="letter-spacing: 1px;font-size: 15px;">hash 算法（大量缓存重建）</span> </section> <section style="box-sizing: border-box;color: rgb(36, 41, 46);font-family: Roboto, sans-serif;font-size: 14px;text-align: justify;white-space: normal;background-color: rgb(255, 255, 255);margin-top: 20px;margin-bottom: 20px;line-height: 1.75em;"> <span style="letter-spacing: 1px;font-size: 15px;">一致性 hash 算法（自动缓存迁移）+ 虚拟节点（自动负载均衡）</span> </section> <section style="box-sizing: border-box;color: rgb(36, 41, 46);font-family: Roboto, sans-serif;font-size: 14px;text-align: justify;white-space: normal;background-color: rgb(255, 255, 255);margin-top: 20px;margin-bottom: 20px;line-height: 1.75em;"> <span style="letter-spacing: 1px;font-size: 15px;">redis cluster 的 hash slot 算法</span> </section> <section style="box-sizing: border-box;color: rgb(36, 41, 46);font-family: Roboto, sans-serif;font-size: 14px;text-align: justify;white-space: normal;background-color: rgb(255, 255, 255);margin-top: 20px;margin-bottom: 20px;line-height: 1.75em;"> <span style="box-sizing: border-box;font-weight: bolder;letter-spacing: 1px;font-size: 15px;">5）hash 算法</span> </section> <section style="box-sizing: border-box;color: rgb(36, 41, 46);font-family: Roboto, sans-serif;font-size: 14px;text-align: justify;white-space: normal;background-color: rgb(255, 255, 255);margin-top: 20px;margin-bottom: 20px;line-height: 1.75em;"> <span style="letter-spacing: 1px;font-size: 15px;">来了一个 key，首先计算 hash 值，然后对节点数取模。</span> </section> <section style="box-sizing: border-box;color: rgb(36, 41, 46);font-family: Roboto, sans-serif;font-size: 14px;text-align: justify;white-space: normal;background-color: rgb(255, 255, 255);margin-top: 20px;margin-bottom: 20px;line-height: 1.75em;"> <span style="letter-spacing: 1px;font-size: 15px;">然后打在不同的 master 节点上。一旦某一个master 节点宕机，所有请求过来，都会基于最新的剩余 master 节点数去取模，尝试去取数据。</span> </section> <section style="box-sizing: border-box;color: rgb(36, 41, 46);font-family: Roboto, sans-serif;font-size: 14px;text-align: justify;white-space: normal;background-color: rgb(255, 255, 255);margin-top: 20px;margin-bottom: 20px;line-height: 1.75em;"> <span style="letter-spacing: 1px;font-size: 15px;">这会导致大部分的请求过来，全部无法拿到有效的缓存，导致大量的流量涌入数据库。</span> </section> <p style="box-sizing: border-box;margin-bottom: 16px;color: rgb(36, 41, 46);font-family: Roboto, sans-serif;font-size: 14px;text-align: left;white-space: normal;background-color: rgb(255, 255, 255);"><img src="/upload/ff879902f87a02347cc6f02adcaff4d8.png" data-type="png" style="box-sizing: content-box;vertical-align: middle;border-style: none;display: block;margin: 20px auto;border-radius: 0px 0px 5px 5px;object-fit: contain;box-shadow: rgb(132, 161, 168) 0px 5px 5px;" data-ratio="0.6901098901098901" data-w="455"></p> <section style="box-sizing: border-box;color: rgb(36, 41, 46);font-family: Roboto, sans-serif;font-size: 14px;text-align: justify;white-space: normal;background-color: rgb(255, 255, 255);margin-top: 20px;margin-bottom: 20px;line-height: 1.75em;"> <span style="box-sizing: border-box;font-weight: bolder;letter-spacing: 1px;font-size: 15px;">6）一致性 hash 算法</span> </section> <section style="box-sizing: border-box;color: rgb(36, 41, 46);font-family: Roboto, sans-serif;font-size: 14px;text-align: justify;white-space: normal;background-color: rgb(255, 255, 255);margin-top: 20px;margin-bottom: 20px;line-height: 1.75em;"> <span style="letter-spacing: 1px;font-size: 15px;">一致性 hash 算法将整个 hash 值空间组织成一个虚拟的圆环，整个空间按顺时针方向组织，下一步将各个 master 节点（使用服务器的 ip 或主机名）进行 hash。这样就能确定每个节点在其哈希环上的位置。</span> </section> <section style="box-sizing: border-box;color: rgb(36, 41, 46);font-family: Roboto, sans-serif;font-size: 14px;text-align: justify;white-space: normal;background-color: rgb(255, 255, 255);margin-top: 20px;margin-bottom: 20px;line-height: 1.75em;"> <span style="letter-spacing: 1px;font-size: 15px;">来了一个 key，首先计算 hash 值，并确定此数据在环上的位置，从此位置沿环顺时针“行走”，遇到的第一个 master 节点就是 key 所在位置。</span> </section> <section style="box-sizing: border-box;color: rgb(36, 41, 46);font-family: Roboto, sans-serif;font-size: 14px;text-align: justify;white-space: normal;background-color: rgb(255, 255, 255);margin-top: 20px;margin-bottom: 20px;line-height: 1.75em;"> <span style="letter-spacing: 1px;font-size: 15px;">在一致性哈希算法中，如果一个节点挂了，受影响的数据仅仅是此节点到环空间前一个节点（沿着逆时针方向行走遇到的第一个节点）之间的数据，其它不受影响。增加一个节点也同理。</span> </section> <section style="box-sizing: border-box;color: rgb(36, 41, 46);font-family: Roboto, sans-serif;font-size: 14px;text-align: justify;white-space: normal;background-color: rgb(255, 255, 255);margin-top: 20px;margin-bottom: 20px;line-height: 1.75em;"> <span style="letter-spacing: 1px;font-size: 15px;">燃鹅，一致性哈希算法在节点太少时，容易因为节点分布不均匀而造成缓存热点的问题。为了解决这种热点问题，一致性 hash 算法引入了虚拟节点机制，即对每一个节点计算多个 hash，每个计算结果位置都放置一个虚拟节点。这样就实现了数据的均匀分布，负载均衡。</span> </section> <p style="box-sizing: border-box;margin-bottom: 16px;color: rgb(36, 41, 46);font-family: Roboto, sans-serif;font-size: 14px;text-align: left;white-space: normal;background-color: rgb(255, 255, 255);"><img src="/upload/34ecd89b018b585839d64bcb8cf34077.jpg" data-type="jpeg" style="box-sizing: content-box;vertical-align: middle;border-style: none;display: block;margin: 20px auto;border-radius: 0px 0px 5px 5px;object-fit: contain;box-shadow: rgb(132, 161, 168) 0px 5px 5px;" data-ratio="1.0440613026819923" data-w="522"></p> <section style="box-sizing: border-box;color: rgb(36, 41, 46);font-family: Roboto, sans-serif;font-size: 14px;text-align: justify;white-space: normal;background-color: rgb(255, 255, 255);margin-top: 20px;margin-bottom: 20px;line-height: 1.75em;"> <span style="box-sizing: border-box;font-weight: bolder;letter-spacing: 1px;font-size: 15px;">7）redis cluster 的 hash slot 算法</span> </section> <section style="box-sizing: border-box;color: rgb(36, 41, 46);font-family: Roboto, sans-serif;font-size: 14px;text-align: justify;white-space: normal;background-color: rgb(255, 255, 255);margin-top: 20px;margin-bottom: 20px;line-height: 1.75em;"> <span style="letter-spacing: 1px;font-size: 15px;">redis cluster 有固定的 16384 个 hash slot，对每个 key 计算 CRC16 值，然后对 16384 取模，可以获取 key 对应的 hash slot。</span> </section> <section style="box-sizing: border-box;color: rgb(36, 41, 46);font-family: Roboto, sans-serif;font-size: 14px;text-align: justify;white-space: normal;background-color: rgb(255, 255, 255);margin-top: 20px;margin-bottom: 20px;line-height: 1.75em;"> <span style="letter-spacing: 1px;font-size: 15px;">redis cluster 中每个 master 都会持有部分 slot，比如有 3 个 master，那么可能每个 master 持有5000 多个 hash slot。hash slot 让 node 的增加和移除很简单，增加一个 master，就将其他 master的 hash slot 移动部分过去，减少一个 master，就将它的 hash slot 移动到其他 master 上去。移动hash slot 的成本是非常低的。客户端的 api，可以对指定的数据，让他们走同一个 hash slot，通过 hash tag 来实现。</span> </section> <section style="box-sizing: border-box;color: rgb(36, 41, 46);font-family: Roboto, sans-serif;font-size: 14px;text-align: justify;white-space: normal;background-color: rgb(255, 255, 255);margin-top: 20px;margin-bottom: 20px;line-height: 1.75em;"> <span style="letter-spacing: 1px;font-size: 15px;">任何一台机器宕机，另外两个节点，不影响的。因为 key 找的是 hash slot，不是机器。</span> </section> <p style="box-sizing: border-box;margin-bottom: 16px;color: rgb(36, 41, 46);font-family: Roboto, sans-serif;font-size: 14px;text-align: left;white-space: normal;background-color: rgb(255, 255, 255);"><img src="/upload/5f54bf462d46ccd7380b4e2bb2fc899d.png" data-type="png" style="box-sizing: content-box;vertical-align: middle;border-style: none;display: block;margin: 20px auto;border-radius: 0px 0px 5px 5px;object-fit: contain;box-shadow: rgb(132, 161, 168) 0px 5px 5px;" data-ratio="0.32857142857142857" data-w="560"></p> <section style="box-sizing: border-box;color: rgb(36, 41, 46);font-family: Roboto, sans-serif;font-size: 14px;text-align: justify;white-space: normal;background-color: rgb(255, 255, 255);margin-top: 20px;margin-bottom: 20px;line-height: 1.75em;"> <br> </section> <section style="box-sizing: border-box;color: rgb(36, 41, 46);font-family: Roboto, sans-serif;font-size: 14px;text-align: justify;white-space: normal;background-color: rgb(255, 255, 255);margin-top: 20px;margin-bottom: 20px;line-height: 1.75em;"> <span style="box-sizing: border-box;font-weight: bolder;letter-spacing: 1px;font-size: 15px;color: rgb(255, 76, 65);">4、redis cluster 的高可用与主备切换原理</span> </section> <section style="box-sizing: border-box;color: rgb(36, 41, 46);font-family: Roboto, sans-serif;font-size: 14px;text-align: justify;white-space: normal;background-color: rgb(255, 255, 255);margin-top: 20px;margin-bottom: 20px;line-height: 1.75em;"> <span style="letter-spacing: 1px;font-size: 15px;">redis cluster 的高可用的原理，几乎跟哨兵是类似的。</span> </section> <section style="box-sizing: border-box;color: rgb(36, 41, 46);font-family: Roboto, sans-serif;font-size: 14px;text-align: justify;white-space: normal;background-color: rgb(255, 255, 255);margin-top: 20px;margin-bottom: 20px;line-height: 1.75em;"> <span style="box-sizing: border-box;font-weight: bolder;letter-spacing: 1px;font-size: 15px;">1）判断节点宕机</span> </section> <section style="box-sizing: border-box;color: rgb(36, 41, 46);font-family: Roboto, sans-serif;font-size: 14px;text-align: justify;white-space: normal;background-color: rgb(255, 255, 255);margin-top: 20px;margin-bottom: 20px;line-height: 1.75em;"> <span style="letter-spacing: 1px;font-size: 15px;">如果一个节点认为另外一个节点宕机，那么就是 pfail，主观宕机。如果多个节点都认为另外一个节点宕机了，那么就是 fail，客观宕机，跟哨兵的原理几乎一样，sdown，odown。</span> </section> <section style="box-sizing: border-box;color: rgb(36, 41, 46);font-family: Roboto, sans-serif;font-size: 14px;text-align: justify;white-space: normal;background-color: rgb(255, 255, 255);margin-top: 20px;margin-bottom: 20px;line-height: 1.75em;"> <span style="letter-spacing: 1px;font-size: 15px;">在 cluster-node-timeout 内，某个节点一直没有返回 pong，那么就被认为 pfail。如果一个节点认为某个节点 pfail 了，那么会在 gossip ping 消息中，ping 给其他节点，如果超过半数的节点都认为 pfail 了，那么就会变成 fail。</span> </section> <section style="box-sizing: border-box;color: rgb(36, 41, 46);font-family: Roboto, sans-serif;font-size: 14px;text-align: justify;white-space: normal;background-color: rgb(255, 255, 255);margin-top: 20px;margin-bottom: 20px;line-height: 1.75em;"> <span style="box-sizing: border-box;font-weight: bolder;letter-spacing: 1px;font-size: 15px;">2）从节点过滤</span> </section> <section style="box-sizing: border-box;color: rgb(36, 41, 46);font-family: Roboto, sans-serif;font-size: 14px;text-align: justify;white-space: normal;background-color: rgb(255, 255, 255);margin-top: 20px;margin-bottom: 20px;line-height: 1.75em;"> <span style="letter-spacing: 1px;font-size: 15px;">对宕机的 master node，从其所有的 slave node 中，选择一个切换成 master node。检查每个 slave node 与 master node 断开连接的时间，如果超过了&nbsp;</span> <code style="box-sizing: border-box;font-family: PingFangSC-Light, SFMono-Regular, Consolas, 'Liberation Mono', Menlo, Courier, monospace;color: rgb(232, 62, 140);word-break: break-word;padding: 0.2em 0.4em;background-color: rgb(238, 238, 238);border-radius: 0px 0px 5px 5px;"><span style="letter-spacing: 1px;font-size: 15px;">cluster-node-timeout *cluster-slave-validity-factor</span></code> <span style="letter-spacing: 1px;font-size: 15px;">，那么就没有资格切换成 master。</span> </section> <section style="box-sizing: border-box;color: rgb(36, 41, 46);font-family: Roboto, sans-serif;font-size: 14px;text-align: justify;white-space: normal;background-color: rgb(255, 255, 255);margin-top: 20px;margin-bottom: 20px;line-height: 1.75em;"> <span style="box-sizing: border-box

<section data-mpa-template="t" mpa-paragraph-type="ignored" style="max-width: 100%;white-space: normal;letter-spacing: 0.544px;background-color: rgb(255, 255, 255);overflow-wrap: break-word !important;box-sizing: border-box !important;" data-mpa-powered-by="yiban.io"> <section data-mpa-template="t" mpa-paragraph-type="ignored" style=""> <section data-mpa-template="t" mpa-paragraph-type="ignored" style="max-width: 100%;letter-spacing: 0.544px;overflow-wrap: break-word !important;box-sizing: border-box !important;"> <section data-mpa-template="t" mpa-paragraph-type="ignored" style="max-width: 100%;letter-spacing: 0.544px;overflow-wrap: break-word !important;box-sizing: border-box !important;"> <section data-mpa-template="t" mpa-paragraph-type="ignored" style="max-width: 100%;letter-spacing: 0.544px;overflow-wrap: break-word !important;box-sizing: border-box !important;"> <section style="white-space: normal;color: rgb(0, 0, 0);font-family: Optima-Regular, Optima, PingFangSC-light, PingFangTC-light, 'PingFang SC', Cambria, Cochin, Georgia, Times, 'Times New Roman', serif;font-size: 16px;letter-spacing: 0.544px;background-color: rgb(255, 255, 255);text-align: center;line-height: 2em;"> <span style="letter-spacing: 0.544px;widows: 1;word-spacing: 2px;caret-color: rgb(51, 51, 51);font-family: Optima-Regular, PingFangTC-light;color: rgb(127, 127, 127);font-size: 14px;line-height: 1.75em;"></span> </section> <p style="max-width: 100%;min-height: 1em;font-family: -apple-system-font, BlinkMacSystemFont, &quot;Helvetica Neue&quot;, &quot;PingFang SC&quot;, &quot;Hiragino Sans GB&quot;, &quot;Microsoft YaHei UI&quot;, &quot;Microsoft YaHei&quot;, Arial, sans-serif;letter-spacing: 0.544px;white-space: normal;background-color: rgb(255, 255, 255);text-align: center;box-sizing: border-box !important;overflow-wrap: break-word !important;"><span style="max-width: 100%;font-family: -apple-system-font, BlinkMacSystemFont, &quot;Helvetica Neue&quot;, &quot;PingFang SC&quot;, 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65);line-height: 22.4px;box-sizing: border-box !important;overflow-wrap: break-word !important;"></span></p> <p style="max-width: 100%;min-height: 1em;font-family: -apple-system-font, system-ui, &quot;Helvetica Neue&quot;, &quot;PingFang SC&quot;, &quot;Hiragino Sans GB&quot;, &quot;Microsoft YaHei UI&quot;, &quot;Microsoft YaHei&quot;, Arial, sans-serif;letter-spacing: 0.544px;white-space: normal;color: rgb(62, 62, 62);font-size: 15px;background-color: rgb(255, 255, 255);text-align: center;box-sizing: border-box !important;overflow-wrap: break-word !important;"><a target="_blank" href="https://mp.weixin.qq.com/mp/appmsgalbum?action=getalbum&amp;album_id=1337172142412169216&amp;__biz=MzIxMTE0ODU5NQ==#wechat_redirect" textvalue="Flink 从入门到精通" tab="innerlink" data-linktype="2" style="color: rgb(120, 172, 254);-webkit-tap-highlight-color: rgba(0, 0, 0, 0);cursor: pointer;max-width: 100%;letter-spacing: 0.544px;font-family: &quot;Helvetica Neue&quot;, Helvetica, &quot;Hiragino Sans GB&quot;, &quot;Microsoft YaHei&quot;, Arial, sans-serif;font-size: 13px;line-height: 1.75em;box-sizing: border-box !important;overflow-wrap: break-word !important;user-select: text !important;"><span style="max-width: 100%;letter-spacing: 0.544px;line-height: 1.75em;box-sizing: border-box !important;overflow-wrap: break-word !important;user-select: text !important;">Flink 从入门到精通</span></a><span style="max-width: 100%;letter-spacing: 0.544px;color: rgb(136, 136, 136);font-family: &quot;Helvetica Neue&quot;, Helvetica, &quot;Hiragino Sans GB&quot;, &quot;Microsoft YaHei&quot;, Arial, sans-serif;font-size: 13px;line-height: 1.75em;box-sizing: border-box !important;overflow-wrap: break-word !important;user-select: text !important;">&nbsp;系列文章</span></p> <p style="white-space: normal;letter-spacing: 0.544px;background-color: rgb(255, 255, 255);color: rgb(62, 62, 62);font-size: 15px;word-spacing: 1px;font-family: -apple-system-font, system-ui, 'Helvetica Neue', 'PingFang SC', 'Hiragino Sans GB', 'Microsoft YaHei UI', 'Microsoft YaHei', Arial, sans-serif;text-align: center;"><span style="color: rgb(136, 136, 136);font-family: Optima-Regular, PingFangTC-light;font-size: 14px;"></span><br></p> </section> </section> </section> </section> </section> <section data-tool="mdnice编辑器" data-website="https://www.mdnice.com" style="max-width: 100%;white-space: normal;overflow-wrap: break-word !important;box-sizing: border-box !important;"> <p style="margin: 5px 8px;max-width: 100%;min-height: 1em;font-size: inherit;text-align: right;overflow-wrap: break-word !important;box-sizing: border-box !important;line-height: 1.6 !important;"><span style="font-size: 14px;font-family: Optima-Regular, PingFangTC-light;color: rgb(136, 136, 136);">toutiao.com/i6843391272229536267</span></p> </section> <p style="margin-left: 8px;margin-right: 8px;line-height: 2em;"><span style="font-size: 15px;font-family: Optima-Regular, PingFangTC-light;">目录<br></span></p> <article data-v-e1fd63b2=""> <ul 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style="line-height: 2em;margin-top: 5px;margin-bottom: 5px;"> <span style="font-size: 15px;font-family: Optima-Regular, PingFangTC-light;">CentOS安装docker</span> </section></li> <li style="font-size: 15px;font-family: Optima-Regular, PingFangTC-light;"> <section style="line-height: 2em;margin-top: 5px;margin-bottom: 5px;"> <span style="font-size: 15px;font-family: Optima-Regular, PingFangTC-light;">通过脚本安装</span> </section></li> </ul> <li style="font-size: 15px;font-family: Optima-Regular, PingFangTC-light;"> <section style="line-height: 2em;margin-top: 5px;margin-bottom: 5px;"> <span style="font-size: 15px;font-family: Optima-Regular, PingFangTC-light;">拉取java环境</span> </section></li> <li style="font-size: 15px;font-family: Optima-Regular, PingFangTC-light;"> <section style="line-height: 2em;margin-top: 5px;margin-bottom: 5px;"> <span style="font-size: 15px;font-family: Optima-Regular, PingFangTC-light;">创建springboot项目</span> </section></li> <li style="font-size: 15px;font-family: Optima-Regular, PingFangTC-light;"> <section style="line-height: 2em;margin-top: 5px;margin-bottom: 5px;"> <span style="font-size: 15px;font-family: Optima-Regular, PingFangTC-light;">打包springboot到docker</span> </section></li> <li style="font-size: 15px;font-family: Optima-Regular, PingFangTC-light;"> <section style="line-height: 2em;margin-top: 5px;margin-bottom: 5px;"> <span style="font-size: 15px;font-family: Optima-Regular, PingFangTC-light;">docker查看容器的日志</span> </section></li> <li style="font-size: 15px;font-family: Optima-Regular, PingFangTC-light;"> <section style="line-height: 2em;margin-top: 5px;margin-bottom: 5px;"> <span style="font-size: 15px;font-family: Optima-Regular, PingFangTC-light;">查看log4j2输出问文件日志</span> </section></li> </ul> <section style="font-size: 16px;color: rgb(51, 51, 51);font-weight: 400;margin: 20px 8px;line-height: 2em;"> <span style="font-size: 15px;font-family: Optima-Regular, PingFangTC-light;">Docker 是一个开源的应用容器引擎，让开发者可以打包他们的应用以及依赖包到一个可移植的镜像中，然后发布到任何流行的 Linux或Windows 机器上，也可以实现虚拟化。容器是完全使用沙箱机制，相互之间不会有任何接口。</span> </section> <section style="font-size: 16px;color: rgb(51, 51, 51);font-weight: 400;margin: 20px 8px;line-height: 2em;"> <span style="font-size: 15px;font-family: Optima-Regular, PingFangTC-light;">docker的核心思想是通过对应用的封装、分发、部署、运行生命周期进行管理，达到应用组件级别的“一次性封装，到处运行”。这里的应用组件，可以是一个web应用，也可以是一个环境，更可以是一个数据库等等。</span> </section> <section style="font-size: 16px;color: rgb(51, 51, 51);font-weight: 400;margin: 20px 8px;line-height: 2em;"> <span style="font-size: 15px;font-family: Optima-Regular, PingFangTC-light;">既然docker这么神奇，那我们如何安装docker呢？我们一起来走一下吧。</span> </section> <section style="font-size: 16px;color: rgb(51, 51, 51);font-weight: 400;margin: 20px 8px;line-height: 2em;"> <span style="font-size: 15px;font-family: Optima-Regular, PingFangTC-light;">PS：我把 Dorcker 相关的文章整理好了，关注微信公众号 Java后端，回复 666 下载就可以了。</span> </section> <h2 style="margin-left: 8px;margin-right: 8px;line-height: 2em;"><strong><span style="font-size: 15px;font-family: Optima-Regular, PingFangTC-light;">Ubuntu安装docker</span></strong></h2> <section style="font-size: 16px;color: rgb(51, 51, 51);font-weight: 400;margin: 20px 8px;line-height: 2em;"> <span style="font-size: 15px;font-family: Optima-Regular, PingFangTC-light;">由于本人的系统是CentOS，所以这里就只展示一下CentOS的安装方式，Ubuntu以及其他系统请自行百度。</span> </section> <h2 style="margin-left: 8px;margin-right: 8px;line-height: 2em;"><strong><span style="font-size: 15px;font-family: Optima-Regular, PingFangTC-light;">CentOS安装docker</span></strong></h2> <section style="font-size: 16px;color: rgb(51, 51, 51);font-weight: 400;margin: 20px 8px;line-height: 2em;"> <span style="font-size: 15px;font-family: Optima-Regular, PingFangTC-light;">docker要求CentOS在7.0以后的版本，如果你的系统版本还在7.0以前，请先升级一下版本在进行安装，同时不支持32位的系统，内核版本至少3.10。</span> </section> <section style="font-size: 16px;color: rgb(51, 51, 51);font-weight: 400;margin: 20px 8px;line-height: 2em;"> <span style="font-size: 15px;font-family: Optima-Regular, PingFangTC-light;">请先确保没有安装过docker，否则有可能会导致安装失败，如果之前安装过，可以尝试直接yum isntall -y docker</span> </section> <section style="font-size: 16px;color: rgb(51, 51, 51);font-weight: 400;margin: 20px 8px;line-height: 2em;"> <span style="font-size: 15px;font-family: Optima-Regular, PingFangTC-light;"><strong>1.更新软件源</strong>第一个命令</span> </section> <section data-mpa-preserve-tpl-color="t" data-mpa-template="t" mpa-preserve="t" mpa-from-tpl="t"> <pre style="margin:0;padding:0;border-radius:none;background:none;"><code style="border-radius: 4px;font-size: 0.85em;margin: 0px 0.15em;background: rgb(248, 248, 248);color: rgb(51, 51, 51);display: block;padding: 5.95px;overflow-x: auto;white-space: nowrap;"><span style="font-size: 13px;">yum <span style="font-size: 13px;color: rgb(51, 51, 51);background: rgba(0, 0, 0, 0);display: inline;width: 43px;text-decoration: none solid rgb(51, 51, 51);font-weight: 700;font-style: normal;">update</span></span></code></pre> </section> <p style="font-size: 16px;line-height: 1.7;color: rgb(51, 51, 51);font-weight: 400;margin: 20px 0px;"><img data-ratio="0.16234887737478412" data-w="579" height="94" src="/upload/4f90ef12d2a70cec5b6075f867775e33.null" style="max-width: 100%;display: block;margin: 20px auto 30px;" width="579"></p> <section style="font-size: 16px;color: rgb(51, 51, 51);font-weight: 400;margin: 20px 8px;line-height: 2em;"> <span style="font-size: 15px;font-family: Optima-Regular, PingFangTC-light;">遇到他输入y，然后回车，看到下面信息表示更新成功：</span> </section> <p style="font-size: 16px;line-height: 1.7;color: rgb(51, 51, 51);font-weight: 400;margin: 20px 0px;"><img data-ratio="0.3546875" data-w="640" height="358" src="/upload/36c58b43bb67b5c1b034fa67c266db9d.null" style="max-width: 100%;display: block;margin: 20px auto 30px;" width="1010"></p> <section style="font-size: 16px;color: rgb(51, 51, 51);font-weight: 400;margin: 20px 8px;line-height: 2em;"> <span style="font-size: 15px;font-family: Optima-Regular, PingFangTC-light;">第二个命令</span> </section> <section data-mpa-preserve-tpl-color="t" data-mpa-template="t" mpa-preserve="t" mpa-from-tpl="t"> <pre style="margin:0;padding:0;border-radius:none;background:none;"><code style="border-radius: 4px;font-size: 0.85em;margin: 0px 0.15em;background: rgb(248, 248, 248);color: rgb(51, 51, 51);display: block;padding: 5.95px;overflow-x: auto;white-space: nowrap;"><span style="font-size: 13px;">yum <span style="font-size: 13px;color: rgb(51, 51, 51);background: rgba(0, 0, 0, 0);display: inline;width: 50px;text-decoration: none solid rgb(51, 51, 51);font-weight: 700;font-style: normal;">install</span>&nbsp;-y yum-utils device-mapper-persistent-<span style="font-size: 13px;color: rgb(51, 51, 51);background: rgba(0, 0, 0, 0);display: inline;width: 29px;text-decoration: none solid rgb(51, 51, 51);font-weight: 700;font-style: normal;">data</span>&nbsp;lvm2</span></code></pre> </section> <p style="font-size: 16px;line-height: 1.7;color: rgb(51, 51, 51);font-weight: 400;margin: 20px 0px;"><img data-ratio="0.3314285714285714" data-w="1050" height="348" src="/upload/df028b4480da45794b54637bde8adba8.null" style="max-width: 100%;display: block;margin: 20px auto 30px;" width="1050"></p> <section style="font-size: 16px;color: rgb(51, 51, 51);font-weight: 400;margin: 20px 8px;line-height: 2em;"> <span style="font-size: 15px;font-family: Optima-Regular, PingFangTC-light;"><strong>2.添加docker稳定版本的yum软件源</strong></span> </section> <pre> <section data-mpa-preserve-tpl-color="t" data-mpa-template="t" mpa-preserve="t" mpa-from-tpl="t"> <pre style="margin:0;padding:0;border-radius:none;background:none;"><code style="border-radius: 4px;font-size: 0.85em;margin: 0px 0.15em;background: rgb(248, 248, 248);color: rgb(51, 51, 51);display: block;padding: 5.95px;overflow-x: auto;white-space: nowrap;"><span style="font-size: 13px;">yum-config-manager --<span style="font-size: 13px;color: rgb(0, 134, 179);background: rgba(0, 0, 0, 0);display: inline;width: 22px;text-decoration: none solid rgb(0, 134, 179);font-weight: 400;font-style: normal;">add</span>-repo http<span style="font-size: 13px;color: rgb(0, 128, 128);background: rgba(0, 0, 0, 0);display: inline;width: 15px;text-decoration: none solid rgb(0, 128, 128);font-weight: 400;font-style: normal;">s:</span>//download.docker.<span style="font-size: 13px;color: rgb(51, 51, 51);background: rgba(0, 0, 0, 0);display: inline;width: 22px;text-decoration: none solid rgb(51, 51, 51);font-weight: 700;font-style: normal;">com</span>/linux/centos/docker-<span style="font-size: 13px;color: rgb(51, 51, 51);background: rgba(0, 0, 0, 0);display: inline;width: 15px;text-decoration: none solid rgb(51, 51, 51);font-weight: 700;font-style: normal;">ce</span>.repo</span></code></pre> </section></pre> <p style="font-size: 16px;line-height: 1.7;color: rgb(51, 51, 51);font-weight: 400;margin: 20px 0px;"><img data-ratio="0.12350119904076738" data-w="834" height="103" src="/upload/667fbed9ede6dfb2cc6bfd23ed39cd09.null" style="max-width: 100%;display: block;margin: 20px auto 30px;" width="834"></p> <section style="font-size: 16px;color: rgb(51, 51, 51);font-weight: 400;margin: 20px 8px;line-height: 2em;"> <span style="font-size: 15px;font-family: Optima-Regular, PingFangTC-light;"><strong>3.再次更新yum源，并安装docker</strong></span> </section> <pre> <section data-mpa-preserve-tpl-color="t" data-mpa-template="t" mpa-preserve="t" mpa-from-tpl="t"> <pre style="margin:0;padding:0;border-radius:none;background:none;"><code style="border-radius: 4px;font-size: 0.85em;margin: 0px 0.15em;background: rgb(248, 248, 248);color: rgb(51, 51, 51);display: block;padding: 5.95px;overflow-x: auto;white-space: nowrap;"><span style="font-size: 13px;">yum <span style="font-size: 13px;color: rgb(51, 51, 51);background: rgba(0, 0, 0, 0);display: inline;width: 43px;text-decoration: none solid rgb(51, 51, 51);font-weight: 700;font-style: normal;">update</span></span></code></pre> </section></pre> <p style="font-size: 16px;line-height: 1.7;color: rgb(51, 51, 51);font-weight: 400;margin: 20px 0px;"><img data-ratio="0.18421052631578946" data-w="950" height="175" src="/upload/3eb919690d158bdd979349c4b781929c.null" style="max-width: 100%;display: block;margin: 20px auto 30px;" width="950"></p> <pre> <section data-mpa-preserve-tpl-color="t" data-mpa-template="t" mpa-preserve="t" mpa-from-tpl="t"> <pre style="margin:0;padding:0;border-radius:none;background:none;"><code style="border-radius: 4px;font-size: 0.85em;margin: 0px 0.15em;background: rgb(248, 248, 248);color: rgb(51, 51, 51);display: block;padding: 5.95px;overflow-x: auto;white-space: nowrap;"><span style="font-size: 13px;">yum <span style="font-size: 13px;color: rgb(51, 51, 51);background: rgba(0, 0, 0, 0);display: inline;width: 50px;text-decoration: none solid rgb(51, 51, 51);font-weight: 700;font-style: normal;">install</span>&nbsp;-y docker-ce</span></code></pre> </section></pre> <p style="font-size: 16px;line-height: 1.7;color: rgb(51, 51, 51);font-weight: 400;margin: 20px 0px;"><img data-ratio="0.19473684210526315" data-w="950" height="185" src="/upload/b9892cb9743448d7bae642ae1399cbd1.null" style="max-width: 100%;display: block;margin: 20px auto 30px;" width="950"></p> <section style="font-size: 16px;color: rgb(51, 51, 51);font-weight: 400;margin: 20px 8px;line-height: 2em;"> <span style="font-size: 15px;font-family: Optima-Regular, PingFangTC-light;">看到这个页面，标识docker已经安装成功了。</span> </section> <section style="font-size: 16px;color: rgb(51, 51, 51);font-weight: 400;margin: 20px 8px;line-height: 2em;"> <span style="font-size: 15px;font-family: Optima-Regular, PingFangTC-light;"><strong>4.安装完成之后启动docker</strong></span> </section> <section data-mpa-preserve-tpl-color="t" data-mpa-template="t" mpa-preserve="t" mpa-from-tpl="t"> <pre style="margin:0;padding:0;border-radius:none;background:none;"><code style="border-radius: 4px;font-size: 0.85em;margin: 0px 0.15em;background: rgb(248, 248, 248);color: rgb(51, 51, 51);display: block;padding: 5.95px;overflow-x: auto;white-space: nowrap;"><span style="font-size: 13px;">systemctl <span style="font-size: 13px;color: rgb(51, 51, 51);background: rgba(0, 0, 0, 0);display: inline;width: 36px;text-decoration: none solid rgb(51, 51, 51);font-weight: 700;font-style: normal;">start</span>&nbsp;docker</span></code></pre> </section> <section style="font-size: 16px;color: rgb(51, 51, 51);font-weight: 400;margin: 20px 8px;line-height: 2em;"> <span style="font-size: 15px;font-family: Optima-Regular, PingFangTC-light;"><strong>5.重启</strong></span> </section> <section data-mpa-preserve-tpl-color="t" data-mpa-template="t" mpa-preserve="t" mpa-from-tpl="t"> <pre style="margin:0;padding:0;border-radius:none;background:none;"><code style="border-radius: 4px;font-size: 0.85em;margin: 0px 0.15em;background: rgb(248, 248, 248);color: rgb(51, 51, 51);display: block;padding: 5.95px;overflow-x: auto;white-space: nowrap;"><span style="font-size: 13px;"><span style="font-size: 13px;color: rgb(0, 0, 128);background: rgba(0, 0, 0, 0);display: inline;width: 65px;text-decoration: none solid rgb(0, 0, 128);font-weight: 400;font-style: normal;">systemctl</span>&nbsp;restart docker</span></code></pre> </section> <section style="font-size: 16px;color: rgb(51, 51, 51);font-weight: 400;margin: 20px 8px;line-height: 2em;"> <span style="font-size: 15px;font-family: Optima-Regular, PingFangTC-light;"><strong>6.停止</strong></span> </section> <section data-mpa-preserve-tpl-color="t" data-mpa-template="t" mpa-preserve="t" mpa-from-tpl="t"> <pre style="margin:0;padding:0;border-radius:none;background:none;"><code style="border-radius: 4px;font-size: 0.85em;margin: 0px 0.15em;background: rgb(248, 248, 248);color: rgb(51, 51, 51);display: block;padding: 5.95px;overflow-x: auto;white-space: nowrap;"><span style="font-size: 13px;">systemctl <span style="font-size: 13px;color: rgb(51, 51, 51);background: rgba(0, 0, 0, 0);display: inline;width: 29px;text-decoration: none solid rgb(51, 51, 51);font-weight: 700;font-style: normal;">stop</span>&nbsp;docker</span></code></pre> </section> <section style="font-size: 16px;color: rgb(51, 51, 51);font-weight: 400;margin: 20px 8px;line-height: 2em;"> <span style="font-size: 15px;font-family: Optima-Regular, PingFangTC-light;"><strong>7.开机自启动</strong></span> </section> <section data-mpa-preserve-tpl-color="t" data-mpa-template="t" mpa-preserve="t" mpa-from-tpl="t"> <pre style="margin:0;padding:0;border-radius:none;background:none;"><code style="border-radius: 4px;font-size: 0.85em;margin: 0px 0.15em;background: rgb(248, 248, 248);color: rgb(51, 51, 51);display: block;padding: 5.95px;overflow-x: auto;white-space: nowrap;"><span style="font-size: 13px;">systemctl <span style="font-size: 13px;color: rgb(0, 134, 179);background: rgba(0, 0, 0, 0);display: inline;width: 43px;text-decoration: none solid rgb(0, 134, 179);font-weight: 400;font-style: normal;">enable</span>&nbsp;docker</span></code></pre> </section> <section style="font-size: 16px;color: rgb(51, 51, 51);font-weight: 400;margin: 20px 8px;line-height: 2em;"> <span style="font-size: 15px;font-family: Optima-Regular, PingFangTC-light;"><strong>8.查看docker的状态</strong></span> </section> <section data-mpa-preserve-tpl-color="t" data-mpa-template="t" mpa-preserve="t" mpa-from-tpl="t"> <pre style="margin:0;padding:0;border-radius:none;background:none;"><code style="border-radius: 4px;font-size: 0.85em;margin: 0px 0.15em;background: rgb(248, 248, 248);color: rgb(51, 51, 51);display: block;padding: 5.95px;overflow-x: auto;white-space: nowrap;"><span style="font-size: 13px;"><span style="font-size: 13px;color: rgb(0, 0, 128);background: rgba(0, 0, 0, 0);display: inline;width: 65px;text-decoration: none solid rgb(0, 0, 128);font-weight: 400;font-style: normal;">systemctl</span>&nbsp;status docker</span></code></pre> </section> <h2 style="margin-left: 8px;margin-right: 8px;line-height: 2em;margin-top: 15px;"><span style="font-size: 15px;font-family: Optima-Regular, PingFangTC-light;">通过脚本安装</span></h2> <section style="font-size: 16px;color: rgb(51, 51, 51);font-weight: 400;margin: 20px 8px;line-height: 2em;"> <span style="font-size: 15px;font-family: Optima-Regular, PingFangTC-light;">除了上面的yum安装，还可以采用shell脚本安装，安装流程如下：</span> </section> <section data-mpa-preserve-tpl-color="t" data-mpa-template="t" mpa-preserve="t" mpa-from-tpl="t"> <pre style="margin:0;padding:0;border-radius:none;background:none;"><code style="border-radius: 4px;font-size: 0.85em;margin: 0px 0.15em;background: rgb(248, 248, 248);color: rgb(51, 51, 51);display: block;padding: 5.95px;overflow-x: auto;white-space: nowrap;"><span style="font-size: 13px;">curl -fsSL http<span style="font-size: 13px;color: rgb(0, 128, 128);background: rgba(0, 0, 0, 0);display: inline;width: 15px;text-decoration: none solid rgb(0, 128, 128);font-weight: 400;font-style: normal;">s:</span>//<span style="font-size: 13px;color: rgb(0, 134, 179);background: rgba(0, 0, 0, 0);display: inline;width: 22px;text-decoration: none solid rgb(0, 134, 179);font-weight: 400;font-style: normal;">get</span>.docker.<span style="font-size: 13px;color: rgb(51, 51, 51);background: rgba(0, 0, 0, 0);display: inline;width: 22px;text-decoration: none solid rgb(51, 51, 51);font-weight: 700;font-style: normal;">com</span>/ | <span style="font-size: 13px;color: rgb(51, 51, 51);background: rgba(0, 0, 0, 0);display: inline;width: 15px;text-decoration: none solid rgb(51, 51, 51);font-weight: 700;font-style: normal;">sh</span></span></code></pre> </section> <section style="font-size: 16px;color: rgb(51, 51, 51);font-weight: 400;margin: 20px 8px;line-height: 2em;"> <span style="font-size: 15px;font-family: Optima-Regular, PingFangTC-light;">或者</span> </section> <section data-mpa-preserve-tpl-color="t" data-mpa-template="t" mpa-preserve="t" mpa-from-tpl="t"> <pre style="margin:0;padding:0;border-radius:none;background:none;"><code style="border-radius: 4px;font-size: 0.85em;margin: 0px 0.15em;background: rgb(248, 248, 248);color: rgb(51, 51, 51);display: block;padding: 5.95px;overflow-x: auto;white-space: nowrap;"><span style="font-size: 13px;">wget -qO- http<span style="font-size: 13px;color: rgb(0, 128, 128);background: rgba(0, 0, 0, 0);display: inline;width: 14px;text-decoration: none solid rgb(0, 128, 128);font-weight: 400;font-style: normal;">s:</span>//<span style="font-size: 13px;color: rgb(0, 134, 179);background: rgba(0, 0, 0, 0);display: inline;width: 21px;text-decoration: none solid rgb(0, 134, 179);font-weight: 400;font-style: normal;">get</span>.docker.<span style="font-size: 13px;color: rgb(51, 51, 51);background: rgba(0, 0, 0, 0);display: inline;width: 22px;text-decoration: none solid rgb(51, 51, 51);font-weight: 700;font-style: normal;">com</span>/ | <span style="font-size: 13px;color: rgb(51, 51, 51);background: rgba(0, 0, 0, 0);display: inline;width: 14px;text-decoration: none solid rgb(51, 51, 51);font-weight: 700;font-style: normal;">sh</span></span></code></pre> </section> <section style="font-size: 16px;color: rgb(51, 51, 51);font-weight: 400;margin: 20px 8px;line-height: 2em;"> <span style="font-size: 15px;font-family: Optima-Regular, PingFangTC-light;">拉取jdk很简单，直接执行一行代码即可，我这里拉取的时java 8的版本。</span> </section> <section data-mpa-preserve-tpl-color="t" data-mpa-template="t" mpa-preserve="t" mpa-from-tpl="t"> <pre style="margin:0;padding:0;border-radius:none;background:none;"><code style="border-radius: 4px;font-size: 0.85em;margin: 0px 0.15em;background: rgb(248, 248, 248);color: rgb(51, 51, 51);display: block;padding: 5.95px;overflow-x: auto;white-space: nowrap;"><span style="font-size: 13px;">docker pull jav<span style="font-size: 13px;color: rgb(0, 128, 128);background: rgba(0, 0, 0, 0);display: inline;width: 22px;text-decoration: none solid rgb(0, 128, 128);font-weight: 400;font-style: normal;">a:8</span></span></code></pre> </section> <section style="font-size: 16px;color: rgb(51, 51, 51);font-weight: 400;margin: 20px 8px;line-height: 2em;"> <span style="font-size: 15px;font-family: Optima-Regular, PingFangTC-light;">拉取完成之后执行：</span> </section> <section data-mpa-preserve-tpl-color="t" data-mpa-template="t" mpa-preserve="t" mpa-from-tpl="t"> <pre style="margin:0;padding:0;border-radius:none;background:none;"><code style="border-radius: 4px;font-size: 0.85em;margin: 0px 0.15em;background: rgb(248, 248, 248);color: rgb(51, 51, 51);display: block;padding: 5.95px;overflow-x: auto;white-space: nowrap;"><span style="font-size: 13px;"><span style="font-size: 13px;color: rgb(0, 0, 128);background: rgba(0, 0, 0, 0);display: inline;width: 43px;text-decoration: none solid rgb(0, 0, 128);font-weight: 400;font-style: normal;">docker</span>&nbsp;images</span></code></pre> </section> <section style="font-size: 16px;color: rgb(51, 51, 51);font-weight: 400;margin: 20px 8px;line-height: 2em;"> <span style="font-size: 15px;font-family: Optima-Regular, PingFangTC-light;">如果出现下面内容，表示拉取成功</span> </section> <p style="font-size: 16px;line-height: 1.7;color: rgb(51, 51, 51);font-weight: 400;margin: 20px 0px;"><img data-ratio="0.11833550065019506" data-w="769" height="91" src="/upload/9270be2db687cc952d4b089c4ac94bab.null" style="max-width: 100%;display: block;margin: 20px auto 30px;" width="769"></p> <section style="font-size: 16px;color: rgb(51, 51, 51);font-weight: 400;margin: 20px 8px;line-height: 2em;"> <span style="font-size: 15px;font-family: Optima-Regular, PingFangTC-light;"><strong>1.新建项目</strong></span> </section> <p style="font-size: 16px;line-height: 1.7;color: rgb(51, 51, 51);font-weight: 400;margin: 20px 0px;"><img data-ratio="0.6796875" data-w="640" height="557" src="/upload/37c81841345c56ef254849ba39483576.null" style="max-width: 100%;display: block;margin: 20px auto 30px;" width="819"></p> <section style="font-size: 16px;color: rgb(51, 51, 51);font-weight: 400;margin: 20px 8px;line-height: 2em;"> <span style="font-size: 15px;font-family: Optima-Regular, PingFangTC-light;">引入sprint-boot-web的依赖</span> </section> <p style="font-size: 16px;line-height: 1.7;color: rgb(51, 51, 51);font-weight: 400;margin: 20px 0px;"><img data-ratio="0.678125" data-w="640" height="555" src="/upload/3f1e4f40aba98a56c3efccb8714d9b2e.null" style="max-width: 100%;display: block;margin: 20px auto 30px;" width="819"></p> <section style="font-size: 16px;color: rgb(51, 51, 51);font-weight: 400;margin: 20px 8px;line-height: 2em;"> <span style="font-size: 15px;font-family: Optima-Regular, PingFangTC-light;">新建完成之后的项目结构</span> </section> <p style="font-size: 16px;line-height: 1.7;color: rgb(51, 51, 51);font-weight: 400;margin: 20px 0px;"><img data-ratio="0.5551601423487544" data-w="281" height="156" src="/upload/556a412136adfcc0ef972b05cbb00494.null" style="max-width: 100%;display: block;margin: 20px auto 30px;" width="281"></p> <section style="font-size: 16px;color: rgb(51, 51, 51);font-weight: 400;margin: 20px 8px;line-height: 2em;"> <span style="font-size: 15px;font-family: Optima-Regular, PingFangTC-light;"><strong>2.引入docker依赖</strong></span> </section> <section data-mpa-preserve-tpl-color="t" data-mpa-template="t" mpa-preserve="t" mpa-from-tpl="t"> <pre style="margin:0;padding:0;border-radius:none;background:none;"><code style="border-radius: 4px;font-size: 0.85em;margin: 0px 0.15em;background: rgb(248, 248, 248);color: rgb(51, 51, 51);display: block;padding: 5.95px;overflow-x: auto;white-space: nowrap;"><span style="font-size: 13px;"><span style="font-size: 13px;color: rgb(0, 0, 128);background: rgba(0, 0, 0, 0);display: inline;width: 86px;text-decoration: none solid rgb(0, 0, 128);font-weight: 400;font-style: normal;">&lt;<span style="color: rgb(0, 0, 128);background: rgba(0, 0, 0, 0);display: inline;width: 72px;text-decoration: none solid rgb(0, 0, 128);font-weight: 400;font-style: normal;">properties</span>&gt;</span><br mpa-from-tpl="t">&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;<span style="font-size: 13px;color: rgb(0, 0, 128);background: rgba(0, 0, 0, 0);display: inline;width: 152px;text-decoration: none solid rgb(0, 0, 128);font-weight: 400;font-style: normal;">&lt;<span style="color: rgb(0, 0, 128);background: rgba(0, 0, 0, 0);display: inline;width: 137px;text-decoration: none solid rgb(0, 0, 128);font-weight: 400;font-style: normal;">docker.image.prefix</span>&gt;</span>registry.aliyuncs.com/linhuatest<span style="font-size: 13px;color: rgb(0, 0, 128);background: rgba(0, 0, 0, 0);display: inline;width: 159px;text-decoration: none solid rgb(0, 0, 128);font-weight: 400;font-style: normal;">&lt;/<span style="color: rgb(0, 0, 128);background: rgba(0, 0, 0, 0);display: inline;width: 137px;text-decoration: none solid rgb(0, 0, 128);font-weight: 400;font-style: normal;">docker.image.prefix</span>&gt;</span><br mpa-from-tpl="t">&nbsp;&nbsp;&nbsp;&nbsp;<span style="font-size: 13px;color: rgb(0, 0, 128);background: rgba(0, 0, 0, 0);display: inline;width: 94px;text-decoration: none solid rgb(0, 0, 128);font-weight: 400;font-style: normal;">&lt;/<span style="color: rgb(0, 0, 128);background: rgba(0, 0, 0, 0);display: inline;width: 72px;text-decoration: none solid rgb(0, 0, 128);font-weight: 400;font-style: normal;">properties</span>&gt;</span><br mpa-from-tpl="t"><br mpa-from-tpl="t"><br mpa-from-tpl="t">&nbsp;<span style="font-size: 13px;color: rgb(153, 153, 136);background: rgba(0, 0, 0, 0);display: inline;width: 132px;text-decoration: none solid rgb(153, 153, 136);font-weight: 400;font-style: italic;">&lt;!-- docker插件 --&gt;</span><br mpa-from-tpl="t">&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;<span style="font-size: 13px;color: rgb(0, 0, 128);background: rgba(0, 0, 0, 0);display: inline;width: 58px;text-decoration: none solid rgb(0, 0, 128);font-weight: 400;font-style: normal;">&lt;<span style="color: rgb(0, 0, 128);background: rgba(0, 0, 0, 0);display: inline;width: 43px;text-decoration: none solid rgb(0, 0, 128);font-weight: 400;font-style: normal;">plugin</span>&gt;</span><br mpa-from-tpl="t">&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;<span style="font-size: 13px;color: rgb(0, 0, 128);background: rgba(0, 0, 0, 0);display: inline;width: 65px;text-decoration: none solid rgb(0, 0, 128);font-weight: 400;font-style: normal;">&lt;<span style="color: rgb(0, 0, 128);background: rgba(0, 0, 0, 0);display: inline;width: 50px;text-decoration: none solid rgb(0, 0, 128);font-weight: 400;font-style: normal;">groupId</span>&gt;</span>com.spotify<span style="font-size: 13px;color: rgb(0, 0, 128);background: rgba(0, 0, 0, 0);display: inline;width: 72px;text-decoration: none solid rgb(0, 0, 128);font-weight: 400;font-style: normal;">&lt;/<span style="color: rgb(0, 0, 128);background: rgba(0, 0, 0, 0);display: inline;width: 51px;text-decoration: none solid rgb(0, 0, 128);font-weight: 400;font-style: normal;">groupId</span>&gt;</span><br mpa-from-tpl="t">&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;<span style="font-size: 13px;color: rgb(0, 0, 128);background: rgba(0, 0, 0, 0);display: inline;width: 87px;text-decoration: none solid rgb(0, 0, 128);font-weight: 400;font-style: normal;">&lt;<span style="color: rgb(0, 0, 128);background: rgba(0, 0, 0, 0);display: inline;width: 72px;text-decoration: none solid rgb(0, 0, 128);font-weight: 400;font-style: normal;">artifactId</span>&gt;</span>docker-maven-plugin<span style="font-size: 13px;color: rgb(0, 0, 128);background: rgba(0, 0, 0, 0);display: inline;width: 94px;text-decoration: none solid rgb(0, 0, 128);font-weight: 400;font-style: normal;">&lt;/<span style="color: rgb(0, 0, 128);background: rgba(0, 0, 0, 0);display: inline;width: 72px;text-decoration: none solid rgb(0, 0, 128);font-weight: 400;font-style: normal;">artifactId</span>&gt;</span><br mpa-from-tpl="t">&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;<span style="font-size: 13px;color: rgb(0, 0, 128);background: rgba(0, 0, 0, 0);display: inline;width: 65px;text-decoration: none solid rgb(0, 0, 128);font-weight: 400;font-style: normal;">&lt;<span style="color: rgb(0, 0, 128);background: rgba(0, 0, 0, 0);display: inline;width: 50px;text-decoration: none solid rgb(0, 0, 128);font-weight: 400;font-style: normal;">version</span>&gt;</span>1.0.0<span style="font-size: 13px;color: rgb(0, 0, 128);background: rgba(0, 0, 0, 0);display: inline;width: 73px;text-decoration: none solid rgb(0, 0, 128);font-weight: 400;font-style: normal;">&lt;/<span style="color: rgb(0, 0, 128);background: rgba(0, 0, 0, 0);display: inline;width: 51px;text-decoration: none solid rgb(0, 0, 128);font-weight: 400;font-style: normal;">version</span>&gt;</span><br mpa-from-tpl="t">&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;<span style="font-size: 13px;color: rgb(0, 0, 128);background: rgba(0, 0, 0, 0);display: inline;width: 109px;text-decoration: none solid rgb(0, 0, 128);font-weight: 400;font-style: normal;">&lt;<span style="color: rgb(0, 0, 128);background: rgba(0, 0, 0, 0);display: inline;width: 93px;text-decoration: none solid rgb(0, 0, 128);font-weight: 400;font-style: normal;">configuration</span>&gt;</span><br mpa-from-tpl="t">&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;<span style="font-size: 13px;color: rgb(0, 0, 128);background: rgba(0, 0, 0, 0);display: inline;width: 80px;text-decoration: none solid rgb(0, 0, 128);font-weight: 400;font-style: normal;">&lt;<span style="color: rgb(0, 0, 128);background: rgba(0, 0, 0, 0);display: inline;width: 65px;text-decoration: none solid rgb(0, 0, 128);font-weight: 400;font-style: normal;">imageName</span>&gt;</span>${docker.image.prefix}/${project.artifactId}<span style="font-size: 13px;color: rgb(0, 0, 128);background: rgba(0, 0, 0, 0);display: inline;width: 86px;text-decoration: none solid rgb(0, 0, 128);font-weight: 400;font-style: normal;">&lt;/<span style="color: rgb(0, 0, 128);background: rgba(0, 0, 0, 0);display: inline;width: 65px;text-decoration: none solid rgb(0, 0, 128);font-weight: 400;font-style: normal;">imageName</span>&gt;</span><br mpa-from-tpl="t">&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;<span style="font-size: 13px;color: rgb(153, 153, 136);background: rgba(0, 0, 0, 0);display: inline;width: 178px;text-decoration: none solid rgb(153, 153, 136);font-weight: 400;font-style: italic;">&lt;!--docker文件所在的目录--&gt;</span><br mpa-from-tpl="t">&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;<span style="font-size: 13px;color: rgb(0, 0, 128);background: rgba(0, 0, 0, 0);display: inline;width: 123px;text-decoration: none solid rgb(0, 0, 128);font-weight: 400;font-style: normal;">&lt;<span style="color: rgb(0, 0, 128);background: rgba(0, 0, 0, 0);display: inline;width: 109px;text-decoration: none solid rgb(0, 0, 128);font-weight: 400;font-style: normal;">dockerDirectory</span>&gt;</span>src/main/docker<span style="font-size: 13px;color: rgb(0, 0, 128);background: rgba(0, 0, 0, 0);display: inline;width: 131px;text-decoration: none solid rgb(0, 0, 128);font-weight: 400;font-style: normal;">&lt;/<span style="color: rgb(0, 0, 128);background: rgba(0, 0, 0, 0);display: inline;width: 108px;text-decoration: none solid rgb(0, 0, 128);font-weight: 400;font-style: normal;">dockerDirectory</span>&gt;</span><br mpa-from-tpl="t">&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;<span style="font-size: 13px;color: rgb(0, 0, 128);background: rgba(0, 0, 0, 0);display: inline;width: 80px;text-decoration: none solid rgb(0, 0, 128);font-weight: 400;font-style: normal;">&lt;<span style="color: rgb(0, 0, 128);background: rgba(0, 0, 0, 0);display: inline;width: 65px;text-decoration: none solid rgb(0, 0, 128);font-weight: 400;font-style: normal;">resources</span>&gt;</span><br mpa-from-tpl="t">&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;<span style="font-size: 13px;color: rgb(0, 0, 128);background: rgba(0, 0, 0, 0);display: inline;width: 72px;text-decoration: none solid rgb(0, 0, 128);font-weight: 400;font-style: normal;">&lt;<span style="color: rgb(0, 0, 128);background: rgba(0, 0, 0, 0);display: inline;width: 58px;text-decoration: none solid rgb(0, 0, 128);font-weight: 400;font-style: normal;">resource</span>&gt;</span><br mpa-from-tpl="t">&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;<span style="font-size: 13px;color: rgb(0, 0, 128);background: rgba(0, 0, 0, 0);display: inline;width: 87px;text-decoration: none solid rgb(0, 0, 128);font-weight: 400;font-style: normal;">&lt;<span style="color: rgb(0, 0, 128);background: rgba(0, 0, 0, 0);display: inline;width: 73px;text-decoration: none solid rgb(0, 0, 128);font-weight: 400;font-style: normal;">targetPath</span>&gt;</span>/<span style="font-size: 13px;color: rgb(0, 0, 128);background: rgba(0, 0, 0, 0);display: inline;width: 94px;text-decoration: none solid rgb(0, 0, 128);font-weight: 400;font-style: normal;">&lt;/<span style="color: rgb(0, 0, 128);background: rgba(0, 0, 0, 0);display: inline;width: 73px;text-decoration: none solid rgb(0, 0, 128);font-weight: 400;font-style: normal;">targetPath</span>&gt;</span><br mpa-from-tpl="t">&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;<span style="font-size: 13px;color: rgb(0, 0, 128);background: rgba(0, 0, 0, 0);display: inline;width: 80px;text-decoration: none solid rgb(0, 0, 128);font-weight: 400;font-style: normal;">&lt;<span style="color: rgb(0, 0, 128);background: rgba(0, 0, 0, 0);display: inline;width: 65px;text-decoration: none solid rgb(0, 0, 128);font-weight: 400;font-style: normal;">directory</span>&gt;</span>${project.build.directory}<span style="font-size: 13px;color: rgb(0, 0, 128);background: rgba(0, 0, 0, 0);display: inline;width: 87px;text-decoration: none solid rgb(0, 0, 128);font-weight: 400;font-style: normal;">&lt;/<span style="color: rgb(0, 0, 128);background: rgba(0, 0, 0, 0);display: inline;width: 65px;text-decoration: none solid rgb(0, 0, 128);font-weight: 400;font-style: normal;">directory</span>&gt;</span><br mpa-from-tpl="t">&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;<span style="font-size: 13px;color: rgb(0, 0, 128);background: rgba(0, 0, 0, 0);display: inline;width: 65px;text-decoration: none solid rgb(0, 0, 128);font-weight: 400;font-style: normal;">&lt;<span style="color: rgb(0, 0, 128);background: rgba(0, 0, 0, 0);display: inline;width: 51px;text-decoration: none solid rgb(0, 0, 128);font-weight: 400;font-style: normal;">include</span>&gt;</span>${project.build.finalName}.jar<span style="font-size: 13px;color: rgb(0, 0, 128);background: rgba(0, 0, 0, 0);display: inline;width: 72px;text-decoration: none solid rgb(0, 0, 128);font-weight: 400;font-style: normal;">&lt;/<span style="color: rgb(0, 0, 128);background: rgba(0, 0, 0, 0);display: inline;width: 51px;text-decoration: none solid rgb(0, 0, 128);font-weight: 400;font-style: normal;">include</span>&gt;</span><br mpa-from-tpl="t">&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;<span style="font-size: 13px;color: rgb(0, 0, 128);background: rgba(0, 0, 0, 0);display: inline;width: 80px;text-decoration: none solid rgb(0, 0, 128);font-weight: 400;font-style: normal;">&lt;/<span style="color: rgb(0, 0, 128);background: rgba(0, 0, 0, 0);display: inline;width: 57px;text-decoration: none solid rgb(0, 0, 128);font-weight: 400;font-style: normal;">resource</span>&gt;</span><br mpa-from-tpl="t">&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;<span style="font-size: 13px;color: rgb(0, 0, 128);background: rgba(0, 0, 0, 0);display: inline;width: 87px;text-decoration: none solid rgb(0, 0, 128);font-weight: 400;font-style: normal;">&lt;/<span style="color: rgb(0, 0, 128);background: rgba(0, 0, 0, 0);display: inline;width: 65px;text-decoration: none solid rgb(0, 0, 128);font-weight: 400;font-style: normal;">resources</span>&gt;</span><br mpa-from-tpl="t">&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;<span style="font-size: 13px;color: rgb(0, 0, 128);background: rgba(0, 0, 0, 0);display: inline;width: 116px;text-decoration: none solid rgb(0, 0, 128);font-weight: 400;font-style: normal;">&lt;/<span style="color: rgb(0, 0, 128);background: rgba(0, 0, 0, 0);display: inline;width: 94px;text-decoration: none solid rgb(0, 0, 128);font-weight: 400;font-style: normal;">configuration</span>&gt;</span><br mpa-from-tpl="t">&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;<span style="font-size: 13px;color: rgb(0, 0, 128);background: rgba(0, 0, 0, 0);display: inline;width: 65px;text-decoration: none solid rgb(0, 0, 128);font-weight: 400;font-style: normal;">&lt;/<span style="font-size: 13px;color: rgb(0, 0, 128);background: rgba(0, 0, 0, 0);display: inline;width: 43px;text-decoration: none solid rgb(0, 0, 128);font-weight: 400;font-style: normal;">plugin</span>&gt;</span></span></code></pre> </section> <section style="font-size: 16px;color: rgb(51, 51, 51);font-weight: 400;margin: 20px 8px;line-height: 2em;"> <span style="font-size: 15px;font-family: Optima-Regular, PingFangTC-light;"><strong>3.新建docker文件</strong>在main目录下新建docker目录，然后在docker目录下创建dockerfile文件，不需要后缀名。</span> <br> </section> <p style="font-size: 16px;line-height: 1.7;color: rgb(51, 51, 51);font-weight: 400;margin: 20px 0px;"><img data-ratio="0.7543186180422264" data-w="521" height="393" src="/upload/3b7d156aa5929b001caaab713f41551f.null" style="max-width: 100%;display: block;margin: 20px auto 30px;" width="521"></p> <section style="font-size: 16px;color: rgb(51, 51, 51);font-weight: 400;margin: 20px 8px;line-height: 2em;"> <span style="font-size: 15px;font-family: Optima-Regular, PingFangTC-light;">创建完成之后的工程目录如下：</span> </section> <p style="font-size: 16px;line-height: 1.7;color: rgb(51, 51, 51);font-weight: 400;margin: 20px 0px;"><img data-ratio="0.648068669527897" data-w="466" height="302" src="/upload/d7fea4a4b0412368161b391a87cc6415.null" style="max-width: 100%;display: block;margin: 20px auto 30px;" width="466"></p> <section style="font-size: 16px;color: rgb(51, 51, 51);font-weight: 400;margin: 20px 8px;line-height: 2em;"> <span style="font-size: 15px;font-family: Optima-Regular, PingFangTC-light;"><strong>4.编辑dockerfile文件</strong></span> </section> <section data-mpa-preserve-tpl-color="t" data-mpa-template="t" mpa-preserve="t" mpa-from-tpl="t"> <pre style="margin:0;padding:0;border-radius:none;background:none;"><code style="border-radius: 4px;font-size: 0.85em;margin: 0px 0.15em;background: rgb(248, 248, 248);color: rgb(51, 51, 51);display: block;padding: 5.95px;overflow-x: auto;white-space: nowrap;"><span style="font-size: 13px;">FROM jav<span style="font-size: 13px;color: rgb(0, 128, 128);background: rgba(0, 0, 0, 0);display: inline;width: 21px;text-decoration: none solid rgb(0, 128, 128);font-weight: 400;font-style: normal;">a:8</span><br mpa-from-tpl="t">VOLUME /tmp/tomcat<br mpa-from-tpl="t">ADD spring-boot-docker-<span style="font-size: 13px;color: rgb(0, 128, 128);background: rgba(0, 0, 0, 0);display: inline;width: 22px;text-decoration: none solid rgb(0, 128, 128);font-weight: 400;font-style: normal;">0.0</span>.<span style="font-size: 13px;color: rgb(0, 128, 128);background: rgba(0, 0, 0, 0);display: inline;width: 7px;text-decoration: none solid rgb(0, 128, 128);font-weight: 400;font-style: normal;">1</span>-SNAPSHOT.jar springboot-docker.jar<br mpa-from-tpl="t">ENTRYPOINT [<span style="font-size: 13px;color: rgb(221, 17, 68);background: rgba(0, 0, 0, 0);display: inline;width: 44px;text-decoration: none solid rgb(221, 17, 68);font-weight: 400;font-style: normal;">"java"</span>,<span style="font-size: 13px;color: rgb(221, 17, 68);background: rgba(0, 0, 0, 0);display: inline;width: 296px;text-decoration: none solid rgb(221, 17, 68);font-weight: 400;font-style: normal;">"-Djava.security.egd=file:/dev/./urandom"</span>,<span style="font-size: 13px;color: rgb(221, 17, 68);background: rgba(0, 0, 0, 0);display: inline;width: 44px;text-decoration: none solid rgb(221, 17, 68);font-weight: 400;font-style: normal;">"-jar"</span>,<span style="font-size: 13px;color: rgb(221, 17, 68);background: rgba(0, 0, 0, 0);display: inline;width: 173px;text-decoration: none solid rgb(221, 17, 68);font-weight: 400;font-style: normal;">"/springboot-docker.jar"</span>]</span></code></pre> </section> <blockquote> <section style="font-size: 16px;color: rgb(51, 51, 51);font-weight: 400;margin: 20px 8px;line-height: 2em;"> <span style="font-size: 15px;font-family: Optima-Regular, PingFangTC-light;">FROM：指定存在的镜像，java:8是我刚刚拉取的镜像，运行的基础。VOLUME：指向的一个临时文件，用于存储tomcat工作。ADD：复制文件并且重命名文件。ENTRYPOINT：初始化配置或者自定义配置。</span> </section> </blockquote> <section style="font-size: 16px;color: rgb(51, 51, 51);font-weight: 400;margin: 20px 8px;line-height: 2em;"> <span style="font-size: 15px;font-family: Optima-Regular, PingFangTC-light;"><strong>5.创建测试接口</strong></span> </section> <p style="font-size: 16px;line-height: 1.7;color: rgb(51, 51, 51);font-weight: 400;margin: 20px 0px;"><img data-ratio="0.25513196480938416" data-w="341" height="87" src="/upload/d20079d5a84cda9ac381ffb5cadae78d.null" style="max-width: 100%;display: block;margin: 20px auto 30px;" width="341"></p> <section style="font-size: 16px;color: rgb(51, 51, 51);font-weight: 400;margin: 20px 8px;line-height: 2em;"> <span style="font-size: 15px;font-family: Optima-Regular, PingFangTC-light;">TestController内容如下：</span> </section> <section data-mpa-preserve-tpl-color="t" data-mpa-template="t" mpa-preserve="t" mpa-from-tpl="t"> <pre style="margin:0;padding:0;border-radius:none;background:none;"><code style="border-radius: 4px;font-size: 0.85em;margin: 0px 0.15em;background: rgb(248, 248, 248);color: rgb(51, 51, 51);display: block;padding: 5.95px;overflow-x: auto;white-space: nowrap;"><span style="font-size: 13px;"><span style="font-size: 13px;color: rgb(51, 51, 51);background: rgba(0, 0, 0, 0);display: inline;width: 50px;text-decoration: none solid rgb(51, 51, 51);font-weight: 700;font-style: normal;">package</span>&nbsp;<span style="font-size: 13px;color: rgb(51, 51, 51);background: rgba(0, 0, 0, 0);display: inline;width: 21px;text-decoration: none solid rgb(51, 51, 51);font-weight: 700;font-style: normal;">com</span><span style="font-size: 13px;color: rgb(51, 51, 51);background: rgba(0, 0, 0, 0);display: inline;width: 29px;text-decoration: none solid rgb(51, 51, 51);font-weight: 400;font-style: normal;">.ymy</span><span style="font-size: 13px;color: rgb(51, 51, 51);background: rgba(0, 0, 0, 0);display: inline;width: 80px;text-decoration: none solid rgb(51, 51, 51);font-weight: 400;font-style: normal;">.controller</span>;<br mpa-from-tpl="t"><br mpa-from-tpl="t"><span style="font-size: 13px;color: rgb(51, 51, 51);background: rgba(0, 0, 0, 0);display: inline;width: 43px;text-decoration: none solid rgb(51, 51, 51);font-weight: 700;font-style: normal;">import</span>&nbsp;<span style="font-size: 13px;color: rgb(51, 51, 51);background: rgba(0, 0, 0, 0);display: inline;width: 44px;text-decoration: none solid rgb(51, 51, 51);font-weight: 700;font-style: normal;">lombok</span><span style="font-size: 13px;color: rgb(51, 51, 51);background: rgba(0, 0, 0, 0);display: inline;width: 50px;text-decoration: none solid rgb(51, 51, 51);font-weight: 400;font-style: normal;">.extern</span><span style="font-size: 13px;color: rgb(51, 51, 51);background: rgba(0, 0, 0, 0);display: inline;width: 44px;text-decoration: none solid rgb(51, 51, 51);font-weight: 400;font-style: normal;">.slf4j</span><span style="font-size: 13px;color: rgb(51, 51, 51);background: rgba(0, 0, 0, 0);display: inline;width: 43px;text-decoration: none solid rgb(51, 51, 51);font-weight: 400;font-style: normal;">.Slf4j</span>;<br mpa-from-tpl="t"><span style="font-size: 13px;color: rgb(51, 51, 51);background: rgba(0, 0, 0, 0);display: inline;width: 43px;text-decoration: none solid rgb(51, 51, 51);font-weight: 700;font-style: normal;">import</span>&nbsp;<span style="font-size: 13px;color: rgb(51, 51, 51);background: rgba(0, 0, 0, 0);display: inline;width: 22px;text-decoration: none solid rgb(51, 51, 51);font-weight: 700;font-style: normal;">org</span><span style="font-size: 13px;color: rgb(51, 51, 51);background: rgba(0, 0, 0, 0);display: inline;width: 116px;text-decoration: none solid rgb(51, 51, 51);font-weight: 400;font-style: normal;">.springframework</span><span style="font-size: 13px;color: rgb(51, 51, 51);background: rgba(0, 0, 0, 0);display: inline;width: 29px;text-decoration: none solid rgb(51, 51, 51);font-weight: 400;font-style: normal;">.web</span><span style="font-size: 13px;color: rgb(51, 51, 51);background: rgba(0, 0, 0, 0);display: inline;width: 36px;text-decoration: none solid rgb(51, 51, 51);font-weight: 400;font-style: normal;">.bind</span><span style="font-size: 13px;color: rgb(51, 51, 51);background: rgba(0, 0, 0, 0);display: inline;width: 79px;text-decoration: none solid rgb(51, 51, 51);font-weight: 400;font-style: normal;">.annotation</span><span style="font-size: 13px;color: rgb(51, 51, 51);background: rgba(0, 0, 0, 0);display: inline;width: 108px;text-decoration: none solid rgb(51, 51, 51);font-weight: 400;font-style: normal;">.RequestMapping</span>;<br mpa-from-tpl="t"><span style="font-size: 13px;color: rgb(51, 51, 51);background: rgba(0, 0, 0, 0);display: inline;width: 43px;text-decoration: none solid rgb(51, 51, 51);font-weight: 700;font-style: normal;">import</span>&nbsp;<span style="font-size: 13px;color: rgb(51, 51, 51);background: rgba(0, 0, 0, 0);display: inline;width: 22px;text-decoration: none solid rgb(51, 51, 51);font-weight: 700;font-style: normal;">org</span><span style="font-size: 13px;color: rgb(51, 51, 51);background: rgba(0, 0, 0, 0);display: inline;width: 116px;text-decoration: none solid rgb(51, 51, 51);font-weight: 400;font-style: normal;">.springframework</span><span style="font-size: 13px;color: rgb(51, 51, 51);background: rgba(0, 0, 0, 0);display: inline;width: 29px;text-decoration: none solid rgb(51, 51, 51);font-weight: 400;font-style: normal;">.web</span><span style="font-size: 13px;color: rgb(51, 51, 51);background: rgba(0, 0, 0, 0);display: inline;width: 36px;text-decoration: none solid rgb(51, 51, 51);font-weight: 400;font-style: normal;">.bind</span><span style="font-size: 13px;color: rgb(51, 51, 51);background: rgba(0, 0, 0, 0);display: inline;width: 79px;text-decoration: none solid rgb(51, 51, 51);font-weight: 400;font-style: normal;">.annotation</span><span style="font-size: 13px;color: rgb(51, 51, 51);background: rgba(0, 0, 0, 0);display: inline;width: 101px;text-decoration: none solid rgb(51, 51, 51);font-weight: 400;font-style: normal;">.RequestMethod</span>;<br mpa-from-tpl="t"><span style="font-size: 13px;color: rgb(51, 51, 51);background: rgba(0, 0, 0, 0);display: inline;width: 43px;text-decoration: none solid rgb(51, 51, 51);font-weight: 700;font-style: normal;">import</span>&nbsp;<span style="font-size: 13px;color: rgb(51, 51, 51);background: rgba(0, 0, 0, 0);display: inline;width: 22px;text-decoration: none solid rgb(51, 51, 51);font-weight: 700;font-style: normal;">org</span><span style="font-size: 13px;color: rgb(51, 51, 51);background: rgba(0, 0, 0, 0);display: inline;width: 116px;text-decoration: none solid rgb(51, 51, 51);font-weight: 400;font-style: normal;">.springframework</span><span style="font-size: 13px;color: rgb(51, 51, 51);background: rgba(0, 0, 0, 0);display: inline;width: 29px;text-decoration: none solid rgb(51, 51, 51);font-weight: 400;font-style: normal;">.web</span><span style="font-size: 13px;color: rgb(51, 51, 51);background: rgba(0, 0, 0, 0);display: inline;width: 36px;text-decoration: none solid rgb(51, 51, 51);font-weight: 400;font-style: normal;">.bind</span><span style="font-size: 13px;color: rgb(51, 51, 51);background: rgba(0, 0, 0, 0);display: inline;width: 79px;text-decoration: none solid rgb(51, 51, 51);font-weight: 400;font-style: normal;">.annotation</span><span style="font-size: 13px;color: rgb(51, 51, 51);background: rgba(0, 0, 0, 0);display: inline;width: 108px;text-decoration: none solid rgb(51, 51, 51);font-weight: 400;font-style: normal;">.RestController</span>;<br mpa-from-tpl="t"><br mpa-from-tpl="t">@<span style="font-size: 13px;color: rgb(51, 51, 51);background: rgba(0, 0, 0, 0);display: inline;width: 101px;text-decoration: none solid rgb(51, 51, 51);font-weight: 700;font-style: normal;">RestController</span><br mpa-from-tpl="t">@Slf4j<br mpa-from-tpl="t">public class TestController {<br mpa-from-tpl="t"><br mpa-from-tpl="t">&nbsp;&nbsp;&nbsp;&nbsp;@<span style="font-size: 13px;color: rgb(51, 51, 51);background: rgba(0, 0, 0, 0);display: inline;width: 101px;text-decoration: none solid rgb(51, 51, 51);font-weight: 700;font-style: normal;">RequestMapping</span>(<span style="font-size: 13px;color: rgb(51, 51, 51);background: rgba(0, 0, 0, 0);display: inline;width: 36px;text-decoration: none solid rgb(51, 51, 51);font-weight: 700;font-style: normal;">value</span>&nbsp;= <span style="font-size: 13px;color: rgb(221, 17, 68);background: rgba(0, 0, 0, 0);display: inline;width: 51px;text-decoration: none solid rgb(221, 17, 68);font-weight: 400;font-style: normal;">"/test"</span>,method = RequestMethod.GET)<br mpa-from-tpl="t">&nbsp;&nbsp;&nbsp;&nbsp;public String test(){<br mpa-from-tpl="t">&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;<span style="font-size: 13px;color: rgb(51, 51, 51);background: rgba(0, 0, 0, 0);display: inline;width: 43px;text-decoration: none solid rgb(51, 51, 51);font-weight: 700;font-style: normal;">System</span><span style="font-size: 13px;color: rgb(51, 51, 51);background: rgba(0, 0, 0, 0);display: inline;width: 29px;text-decoration: none solid rgb(51, 51, 51);font-weight: 400;font-style: normal;">.out</span><span style="font-size: 13px;color: rgb(51, 51, 51);background: rgba(0, 0, 0, 0);display: inline;width: 58px;text-decoration: none solid rgb(51, 51, 51);font-weight: 400;font-style: normal;">.println</span>("这是控制台日志！");<br mpa-from-tpl="t">&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;<span style="font-size: 13px;color: rgb(51, 51, 51);background: rgba(0, 0, 0, 0);display: inline;width: 21px;text-decoration: none solid rgb(51, 51, 51);font-weight: 700;font-style: normal;">log</span><span style="font-size: 13px;color: rgb(51, 51, 51);background: rgba(0, 0, 0, 0);display: inline;width: 36px;text-decoration: none solid rgb(51, 51, 51);font-weight: 400;font-style: normal;">.info</span>("这是输出到文件的日志");<br mpa-from-tpl="t">&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;<span style="font-size: 13px;color: rgb(51, 51, 51);background: rgba(0, 0, 0, 0);display: inline;width: 43px;text-decoration: none solid rgb(51, 51, 51);font-weight: 700;font-style: normal;">return</span>&nbsp;&nbsp;&nbsp;"<span style="font-size: 13px;color: rgb(51, 51, 51);background: rgba(0, 0, 0, 0);display: inline;width: 65px;text-decoration: none solid rgb(51, 51, 51);font-weight: 700;font-style: normal;">HELLO-BUG</span>！！！！！！！！！！";<br mpa-from-tpl="t">&nbsp;&nbsp;&nbsp;&nbsp;}<br mpa-from-tpl="t">}</span><span style=""></span></code></pre> </section> <section style="font-size: 16px;color: rgb(51, 51, 51);font-weight: 400;margin: 20px 8px;line-height: 2em;"> <span style="font-size: 15px;font-family: Optima-Regular, PingFangTC-light;">在resources目录下创建log4j2.xml文件主要看这两个参数�