Spring Cloud之Eureka对服务的监控处理等

一，应用场景：多个服务启动后可能会因为一些其他或者内在原因导致服务会挂掉，而我们维护人员不知情的情况下服务会一直挂到有人发现为止，

所以我们需要对Eureka的各个服务进行监听，当他们发生上线，下线，启动等，利用短信，邮箱等通知维护人员，维护人员会第一时间了解服务情况，进行处理。

二.Eureka服务状态分类

Eureka的server端会发出5个事件通知，分别是：

2.1 EurekaInstanceCanceledEvent 当有服务下线时会执行（掉线顾名思义，就是某个服务关闭时触发）
2.2 EurekaInstanceRegisteredEvent 当有服务注册时会执行（注册中心检测到有新的服务注册进来时触发）
2.3 EurekaInstanceRenewedEvent 当有服务续约时会执行（服务设置了心跳时间，如果下一次心跳还正常，就会把服务续约的信息更新到自身的Eureka Server中，然后再同步到其它Eureka Server中）
2.4 EurekaRegistryAvailableEvent Eureka 注册中心启动执行

2.5 EurekaServerStartedEvent Eureka Server 启动时执行

那接下来就好说了

第一步 : 引入maven依赖

略: 就是基本的依赖

第二步 : 监听服务

在网上查询了部分资料之后,发现部分的博客缺少一些东西,会对新手有很多的误导,在这里给出一个详细的步骤

Eureka服务端的配置

server:
  port: 9999

spring:
  application:
    name: eureka01
  security:
    user:
      name: root
      password: root

eureka:
  client:
    register-with-eureka: false #是否注册给服务中心，本身就是注册中心，所以不需要注册
    service-url:
      defaultZone: http://root:root@localhost:9997/eureka/,http://root:root@localhost:9998/eureka/   #分别指向除自己外的注册中心地址，多个地址之间用“,”号隔开
  server:
    enable-self-preservation: false   # 测试时关闭自我保护机制，保证不可用服务及时踢出
    eviction-interval-timer-in-ms: 5000 # 续期时间，即扫描失效服务的间隔时间（缺省为60*1000ms）

服务配置这里的关闭自我保护和清理间隔一定要打开 (虽然我也不知道为什么)

启动类

package com.web;

import org.springframework.boot.SpringApplication;
import org.springframework.boot.autoconfigure.SpringBootApplication;
import org.springframework.cloud.netflix.eureka.server.EnableEurekaServer;
import org.springframework.security.config.annotation.web.builders.HttpSecurity;
import org.springframework.security.config.annotation.web.configuration.WebSecurityConfigurerAdapter;
/**
 * Hello world!
 *
 */
@SpringBootApplication
@EnableEurekaServer
public class EurekaServer  extends WebSecurityConfigurerAdapter{
    public static void main( String[] args ) {

        SpringApplication.run(EurekaServer.class, args);
    }
    @Override
    protected void configure(HttpSecurity http) throws Exception {
        http.csrf().disable();//关闭csrf
        super.configure(http);
    }
}

服务监听类

package com.web.event;

import com.netflix.appinfo.InstanceInfo;
import lombok.extern.log4j.Log4j2;
import org.springframework.cloud.netflix.eureka.server.event.*;
import org.springframework.context.event.EventListener;
import org.springframework.stereotype.Component;

@Log4j2
@Component
public class EurekaStateListener {
    //private final static Logger logger = LoggerFactory.getLogger(EurekaStateListener.class);

    @EventListener
    public void listen(EurekaInstanceCanceledEvent event) {
        log.info("服务{}已下线", event.getAppName());
        log.info("server地址信息{}", event.getServerId());
    }

    @EventListener
    public void listen(EurekaInstanceRegisteredEvent event) {
        InstanceInfo instanceInfo = event.getInstanceInfo();
        log.info("服务{}进行注册", instanceInfo.getAppName()+ instanceInfo.getHostName() +"  "+ instanceInfo.getIPAddr() +"  "+ instanceInfo.getPort());
    }

    @EventListener
    public void listen(EurekaInstanceRenewedEvent event) {
        log.info("服务{}进行续约", event.getServerId() +"  "+ event.getAppName());
    }

    @EventListener
    public void listen(EurekaRegistryAvailableEvent event) {
        log.info("注册中心启动,{}", System.currentTimeMillis());
    }

    @EventListener
    public void listen(EurekaServerStartedEvent event) {
        log.info("注册中心服务端启动,{}", System.currentTimeMillis());
    }
}

这里只是简单的记录,实际项目还是要做大量的通知，如果有注册中心是集群，挨个如上配置即可，我这就是集群的配置，以一个作文样列，就不每个都展示出来了。

第三步 : 客户端

客户端配置

server:
  port: 8032

spring:
  application:
    name: productAclient

eureka:
  instance:
    lease-renewal-interval-in-seconds: 1 #每间隔10s，向服务端发送一次心跳
    lease-expiration-duration-in-seconds: 2 #如果我2s之内没有给你发心跳，就代表我“死”了，将我踢出掉。
    prefer-ip-address: true
    hostname: 192.168.1.83
    instance-id:  ${eureka.instance.hostname}:${server.port}
  client:
    service-url:
      defaultZone: http://root:root@localhost:9998/eureka/,http://root:root@localhost:9997/eureka/,http://root:root@localhost:9999/eureka/

这里的instance配置一定要写,很多新手忘记写这个导致服务下线无法被监听,因为服务下线后eureka没有将该服务踢出

启动类

package com.web;

import org.springframework.boot.SpringApplication;
import org.springframework.boot.autoconfigure.SpringBootApplication;
import org.springframework.cloud.netflix.eureka.EnableEurekaClient;

/**
 * Hello world!
 *
 */
@SpringBootApplication
@EnableEurekaClient
public class productA_Client {

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

    }


}

第四步 : 测试看效果

启动注册中心

2019-07-10 11:10:33.966  INFO 17696 --- [      Thread-30] c.n.e.r.PeerAwareInstanceRegistryImpl    : Changing status to UP
2019-07-10 11:10:33.974  INFO 17696 --- [      Thread-30] e.s.EurekaServerInitializerConfiguration : Started Eureka Server
2019-07-10 11:10:33.977  INFO 17696 --- [      Thread-30] com.web.event.EurekaStateListener        : 注册中心启动,1562728233974
2019-07-10 11:10:33.978  INFO 17696 --- [      Thread-30] com.web.event.EurekaStateListener        : 注册中心服务端启动,1562728233978
2019-07-10 11:10:33.990  INFO 17696 --- [           main] o.s.b.w.embedded.tomcat.TomcatWebServer  : Tomcat started on port(s): 9998 (http) with context path ''
2019-07-10 11:10:33.991  INFO 17696 --- [           main] .s.c.n.e.s.EurekaAutoServiceRegistration : Updating port to 9998

服务注册

2019-07-10 11:10:35.860  INFO 17696 --- [nio-9998-exec-3] com.web.event.EurekaStateListener        : 服务PRODUCTACLIENT192.168.1.83  192.168.1.83  8031进行注册
2019-07-10 11:10:35.875  INFO 17696 --- [nio-9998-exec-3] c.n.e.registry.AbstractInstanceRegistry  : Registered instance PRODUCTACLIENT/192.168.1.83:8031 with status UP (replication=true)
2019-07-10 11:10:35.876  INFO 17696 --- [nio-9998-exec-3] com.web.event.EurekaStateListener        : 服务PRODUCTACLIENT192.168.1.83  192.168.1.83  8030进行注册
2019-07-10 11:10:35.876  INFO 17696 --- [nio-9998-exec-3] c.n.e.registry.AbstractInstanceRegistry  : Registered instance PRODUCTACLIENT/192.168.1.83:8030 with status UP (replication=true)
2019-07-10 11:10:36.389  INFO 17696 --- [nio-9998-exec-4] com.web.event.EurekaStateListener        : 服务PRODUCTACLIENT192.168.1.83  192.168.1.83  8031进行注册
2019-07-10 11:10:36.389  INFO 17696 --- [nio-9998-exec-4] c.n.e.registry.AbstractInstanceRegistry  : Registered instance PRODUCTACLIENT/192.168.1.83:8031 with status UP (replication=true)
2019-07-10 11:10:36.390  INFO 17696 --- [nio-9998-exec-4] com.web.event.EurekaStateListener        : 服务192.168.1.83:8030  PRODUCTACLIENT进行续约
2019-07-10 11:10:36.391  INFO 17696 --- [nio-9998-exec-4] com.web.event.EurekaStateListener        : 服务192.168.1.83:8031  PRODUCTACLIENT进行续约
2019-07-10 11:10:37.407  INFO 17696 --- [nio-9998-exec-5] com.web.event.EurekaStateListener        : 服务192.168.1.83:8030  PRODUCTACLIENT进行续约
2019-07-10 11:10:37.408  INFO 17696 --- [nio-9998-exec-5] com.web.event.EurekaStateListener        : 服务192.168.1.83:8031  PRODUCTACLIENT进行续约
2019-07-10 11:10:38.415  INFO 17696 --- [nio-9998-exec-6] com.web.event.EurekaStateListener        : 服务192.168.1.83:8030  PRODUCTACLIENT进行续约
2019-07-10 11:10:38.416  INFO 17696 --- [nio-9998-exec-6] com.web.event.EurekaStateListener        : 服务192.168.1.83:8031  PRODUCTACLIENT进行续约
2019-07-10 11:10:38.967  INFO 17696 --- [a-EvictionTimer] c.n.e.registry.AbstractInstanceRegistry  : Running the evict task with compensationTime 0ms

停止8082端口的服务

2018-07-24 09:41:59.599  INFO 16524 --- [a-EvictionTimer] com.lh.event.EurekaStateListener         : 服务MEMBER已下线
2018-07-24 09:41:59.600  INFO 16524 --- [a-EvictionTimer] com.lh.event.EurekaStateListener         : server地址信息DESKTOP-SHDQ5I0:member:8082
2018-07-24 09:41:59.601  INFO 16524 --- [a-EvictionTimer] c.n.e.registry.AbstractInstanceRegistry  : Cancelled instance MEMBER/DESKTOP-SHDQ5I0:member:8082 (replication=false)