在很多时候 kill -9 pid并不是很友好的方法，那样会将我们正在执行请求给断掉，同时eureka 中服务依旧是处于在线状态，这个时候我们可以使用官方提供的actuator来做优雅的关闭处理

- Actuator

spring-boot-actuator模块提供了一个监控和管理生产环境的模块，可以使用http、jmx、ssh、telnet等拉管理和监控应用。审计（Auditing）、健康（health）、数据采集（metrics gathering）会自动加入到应用里面。

SRE实战 互联网时代守护先锋，助力企业售后服务体系运筹帷幄！一键直达领取阿里云限量特价优惠。

- 开始

如果对Eureka不熟悉的可以参考：一起来学SpringCloud之-注册中心（Eureka/Consul）

- battcn-cloud-discovery

pom.xml导入eureka-server包

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<dependencies>
 <dependency>
 <groupId>org.springframework.cloud</groupId>
 <artifactId>spring-cloud-starter-eureka-server</artifactId>
 </dependency>
</dependencies>

application.yml 配置内容

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server:
 port: 7001
spring:
 application:
 name: battcn-cloud-discovery
eureka:
 instance:
 hostname: localhost
 prefer-ip-address: true
 client:
 register-with-eureka: false
 fetch-registry: false
 service-url:
 defaultZone: http://${eureka.instance.hostname}:${server.port}/eureka/

DiscoveryApplication 主函数启动类

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@SpringBootApplication
@EnableEurekaServer
public class DiscoveryApplication {
 public static void main(String[] args) {
 SpringApplication.run(DiscoveryApplication.class, args);
 }
}

- battcn-cloud-hello

pom.xml导入eureka和actuator，注意该处不能用tomcat（原因还没找到，用tomcat报错，有兴趣的可以自己也试试）

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<dependencies>
 <dependency>
 <groupId>org.springframework.cloud</groupId>
 <artifactId>spring-cloud-starter-eureka</artifactId>
 <exclusions>
 <exclusion>
 <groupId>org.springframework.boot</groupId>
 <artifactId>spring-boot-starter-tomcat</artifactId>
 </exclusion>
 </exclusions>
 </dependency>
 <dependency>
 <groupId>org.springframework.boot</groupId>
 <artifactId>spring-boot-starter-jetty</artifactId>
 </dependency>
 <dependency>
 <groupId>org.springframework.boot</groupId>
 <artifactId>spring-boot-starter-actuator</artifactId>
 </dependency>
</dependencies>

application.yml 配置内容

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server.port: 7002
spring.application.name: battcn-cloud-hello
endpoints.shutdown.enabled: true #开启优雅关闭方式
management.security.enabled: false #关闭安全认证
eureka:
 instance:
 hostname: localhost
 prefer-ip-address: true
 client:
 service-url:
 defaultZone: http://${eureka.instance.hostname}:7001/eureka/

HelloApplication 主函数与测试方法

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import org.slf4j.Logger;
import org.slf4j.LoggerFactory;
import org.springframework.boot.SpringApplication;
import org.springframework.boot.autoconfigure.SpringBootApplication;
import org.springframework.cloud.client.discovery.EnableDiscoveryClient;
import org.springframework.web.bind.annotation.GetMapping;
import org.springframework.web.bind.annotation.RestController;

@SpringBootApplication
@EnableDiscoveryClient
@RestController
public class HelloApplication {
 static Logger LOGGER = LoggerFactory.getLogger(HelloApplication.class);
 @GetMapping("/h1")
 public void home() {
 for (int i = 1;i < 6;i++) {
 try {
 Thread.sleep(i * 500);
 } catch (InterruptedException e) {
 e.printStackTrace();
 }
 LOGGER.info("[当前进度] - [{}]",i);
 }
 }

 public static void main(String[] args) {
 SpringApplication.run(HelloApplication.class, args);
 }
}

- 测试

1.分别启动battcn-cloud-discovery 和 battcn-cloud-hello两个服务

2.GET请求访问 http://192.168.206.1:7002/h1

3.POST请求访问：http://192.168.206.1:7002/shutdown

优雅关闭服务下线（Jetty） 随笔PostMan

- 日志分析

  • battcn-cloud-discovery
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2017-08-20 11:50:38.257  INFO 6776 --- [nio-7001-exec-3] c.n.e.registry.AbstractInstanceRegistry  : Registered instance BATTCN-CLOUD-HELLO/192.168.206.1:battcn-cloud-hello:7002 with status DOWN (replication=false)
2017-08-20 11:50:38.259 INFO 6776 --- [nio-7001-exec-8] c.n.e.registry.AbstractInstanceRegistry : Cancelled instance BATTCN-CLOUD-HELLO/192.168.206.1:battcn-cloud-hello:7002 (replication=false)
2017-08-20 11:50:38.765 INFO 6776 --- [nio-7001-exec-5] c.n.e.registry.AbstractInstanceRegistry : Registered instance BATTCN-CLOUD-HELLO/192.168.206.1:battcn-cloud-hello:7002 with status DOWN (replication=true)
2017-08-20 11:50:38.766 INFO 6776 --- [nio-7001-exec-5] c.n.e.registry.AbstractInstanceRegistry : Cancelled instance BATTCN-CLOUD-HELLO/192.168.206.1:battcn-cloud-hello:7002 (replication=true)
  • battcn-cloud-hello
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2017-08-20 11:50:34.911  INFO 1304 --- [qtp161672347-19] com.battcn.HelloApplication              : [当前进度] - [1]
2017-08-20 11:50:35.912 INFO 1304 --- [qtp161672347-19] com.battcn.HelloApplication : [当前进度] - [2]
2017-08-20 11:50:37.413 INFO 1304 --- [qtp161672347-19] com.battcn.HelloApplication : [当前进度] - [3]
2017-08-20 11:50:38.251 INFO 1304 --- [ Thread-28] ationConfigEmbeddedWebApplicationContext : Closing org.springframework.boot.context.embedded.AnnotationConfigEmbeddedWebApplicationContext@1c481ff2: startup date [Sun Aug 20 11:50:24 CST 2017]; parent: org.springframework.context.annotation.AnnotationConfigApplicationContext@60dcc9fe
2017-08-20 11:50:38.252 INFO 1304 --- [ Thread-28] o.s.c.n.e.s.EurekaServiceRegistry : Unregistering application battcn-cloud-hello with eureka with status DOWN
2017-08-20 11:50:38.252 WARN 1304 --- [ Thread-28] com.netflix.discovery.DiscoveryClient : Saw local status change event StatusChangeEvent [timestamp=1503201038252, current=DOWN, previous=UP]
2017-08-20 11:50:38.252 INFO 1304 --- [ Thread-28] com.netflix.discovery.DiscoveryClient : Shutting down DiscoveryClient ...
2017-08-20 11:50:38.252 INFO 1304 --- [nfoReplicator-0] com.netflix.discovery.DiscoveryClient : DiscoveryClient_BATTCN-CLOUD-HELLO/192.168.206.1:battcn-cloud-hello:7002: registering service...
2017-08-20 11:50:38.253 INFO 1304 --- [ Thread-28] com.netflix.discovery.DiscoveryClient : Unregistering ...
2017-08-20 11:50:38.258 INFO 1304 --- [nfoReplicator-0] com.netflix.discovery.DiscoveryClient : DiscoveryClient_BATTCN-CLOUD-HELLO/192.168.206.1:battcn-cloud-hello:7002 - registration status: 204
2017-08-20 11:50:38.260 INFO 1304 --- [ Thread-28] com.netflix.discovery.DiscoveryClient : DiscoveryClient_BATTCN-CLOUD-HELLO/192.168.206.1:battcn-cloud-hello:7002 - deregister status: 200
2017-08-20 11:50:38.264 INFO 1304 --- [ Thread-28] com.netflix.discovery.DiscoveryClient : Completed shut down of DiscoveryClient
2017-08-20 11:50:38.265 INFO 1304 --- [ Thread-28] o.s.c.support.DefaultLifecycleProcessor : Stopping beans in phase 0
2017-08-20 11:50:38.269 INFO 1304 --- [ Thread-28] o.s.j.e.a.AnnotationMBeanExporter : Unregistering JMX-exposed beans on shutdown
2017-08-20 11:50:38.270 INFO 1304 --- [ Thread-28] o.s.j.e.a.AnnotationMBeanExporter : Unregistering JMX-exposed beans
2017-08-20 11:50:38.283 INFO 1304 --- [ Thread-28] o.e.jetty.server.AbstractConnector : Stopped ServerConnector@622fdb81{HTTP/1.1,[http/1.1]}{0.0.0.0:7002}
2017-08-20 11:50:38.283 INFO 1304 --- [ Thread-28] org.eclipse.jetty.server.session : Stopped scavenging
2017-08-20 11:50:38.290 INFO 1304 --- [ Thread-28] o.e.j.s.h.ContextHandler.application : Destroying Spring FrameworkServlet 'dispatcherServlet'
2017-08-20 11:50:38.291 INFO 1304 --- [ Thread-28] o.e.jetty.server.handler.ContextHandler : Stopped o.s.b.c.e.j.JettyEmbeddedWebAppContext@987455b{/,[file:///C:/Users/Levin/AppData/Local/Temp/jetty-docbase.3368921683179226836.7002/],UNAVAILABLE}
2017-08-20 11:50:39.414 INFO 1304 --- [qtp161672347-19] com.battcn.HelloApplication : [当前进度] - [4]
2017-08-20 11:50:41.915 INFO 1304 --- [qtp161672347-19] com.battcn.HelloApplication : [当前进度] - [5]

从上述两端日志中可以看出，当我们发送shutdown命令的时候，会先通知eureka做服务下线处理，防止后续请求继续获取服务列表，然后当前服务的请求会继续执行，直到处理完毕后关闭进程，有兴趣的可以自己看看org.springframework.boot.actuate.endpoint.ShutdownEndpoint

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