springboot + nginx 项目无感知发版

要点

1. springboot项目

2. spring-boot-starter-actuator插件

3. 定制化tomcat关闭回调

4. nginx 负载均衡(至少两台机器)

代码实现

1、引入pom

<dependencies>
    <!--集成springmvc框架并实现自动配置 -->
    <dependency>
        <groupId>org.springframework.boot</groupId>
        <artifactId>spring-boot-starter-web</artifactId>
    </dependency>
 
 
    <dependency>
        <groupId>org.springframework.boot</groupId>
        <artifactId>spring-boot-starter-actuator</artifactId>
    </dependency>
</dependencies>

2、定制化tomcat回调

CustomShutdown

/**
 * @author lixiaoyi
 * @description 定制shutdown 关闭逻辑
 *  1、 先暂停所有请求
 *  2、 等待现有线程处理完
 *  3、 关闭线程
 * @date 2021/7/22
 **/
@Slf4j
public class CustomShutdown implements TomcatConnectorCustomizer, ApplicationListener<ContextClosedEvent> {
 
 
    private static final int TIME_OUT = 30;
 
 
    private volatile Connector connector;
 
 
    @Override
    public void customize(Connector connector) {
        this.connector = connector;
    }
 
 
    @Override
    public void onApplicationEvent(ContextClosedEvent event) {
 
 
        /* 暂停所有请求 */
        this.connector.pause();
 
 
        /* 获取tomcat的线程池 */
        Executor executor = this.connector.getProtocolHandler().getExecutor();
        if (executor instanceof ThreadPoolExecutor) {
            try {
                ThreadPoolExecutor threadPoolExecutor = (ThreadPoolExecutor) executor;
                /* 关闭线程 （等待线程处理完之后）*/
                threadPoolExecutor.shutdown();
                if (!threadPoolExecutor.awaitTermination(TIME_OUT, TimeUnit.SECONDS)) {
                    log.warn("当前应用等待超过最大时长{}秒，将强制关闭", TIME_OUT);
                    /* Try shutDown Now*/
                    threadPoolExecutor.shutdownNow();
                    if (!threadPoolExecutor.awaitTermination(TIME_OUT, TimeUnit.SECONDS)) {
                        log.error("强制关闭失败", TIME_OUT);
                    }
                }
            } catch (InterruptedException e) {
                Thread.currentThread().interrupt();
            }
        }
 
 
    }
}

ShutdownConfig

@Configuration
public class ShutdownConfig {
 
 
    @Bean
    public CustomShutdown customShutdown() {
        return new CustomShutdown();
    }
 
 
    @Bean
    public ConfigurableServletWebServerFactory webServerFactory(final CustomShutdown customShutdown) {
        TomcatServletWebServerFactory tomcatServletWebServerFactory = new TomcatServletWebServerFactory();
        tomcatServletWebServerFactory.addConnectorCustomizers(customShutdown);
        return tomcatServletWebServerFactory;
    }
}

测试例子

@RestController
public class TestController {
 
 
    @RequestMapping("/test")
    public String test() throws InterruptedException {
        System.out.println("test");
        Thread.sleep(30000);
        String s = System.currentTimeMillis()+"";
        System.out.println("返回结果:"+s);
        return s;
    }
 
 
    @RequestMapping("/test1")
    public String test1() {
        System.out.println("test1");
        return "test1";
    }
}

3、nginx配置

http {
    include       mime.types;
    default_type  application/octet-stream;
 
    sendfile        on;
 
    keepalive_timeout  65;
 
 
    #gzip  on;
 
 
    upstream backend {
       server localhost:8888;
       server localhost:8889;
      }
 
 
    server {
        listen       80;
        server_name  localhost;
 
 
        #charset koi8-r;
 
 
        #access_log  logs/host.access.log  main;
 
 
        location / {
             proxy_pass http://backend;
        }
 
 
        #error_page  404              /404.html;
 
 
        error_page   500 502 503 504  /50x.html;
        location = /50x.html {
            root   html;
        }
 
    }
 
}

操作流程

1. 业务请求： http://localhost/test   30s 返回结果

2. 注释 nginx 配置  server localhost:8888;

3. 刷新nginx配置  nginx -s reload

4. 关闭应用 http://localhost:8888/actuator/shutdown

5. 重新启动关闭应用

6. 启动完成 重复 2 3 4 5 步骤，第二步注释8889的机器