优雅关闭服务下线（Jetty）

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。

- 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

1 2 3 4 5 6

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

application.yml 配置内容

1 2 3 4 5 6 7 8 9 10 11 12 13 14

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

1 2 3 4 5 6 7

@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）

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20

<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

1 2 3 4 5 6 7 8 9 10 11

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

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29

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

PostMan

- 日志分析

• battcn-cloud-discovery

1 2 3 4

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

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21

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