SpringBoot-Admin 2.X 微服务监控+健康检查+钉钉告警部署踩坑记录

继上一篇 SpringBoot-Admin 微服务监控+健康检查+钉钉告警，附代码配置
项目部署上线后，会偶尔出现下面的异常，导致告警消息并非是真正服务实例出现异常，

{
    "statusInfo": {
        "status": "OFFLINE",
        "details": {
            "exception": "org.springframework.web.reactive.function.client.WebClientRequestException",
            "message": "Connection prematurely closed BEFORE response; nested exception is reactor.netty.http.client.PrematureCloseException: Connection prematurely closed BEFORE response"
        }
    }
}

经查看服务器日志，同样出现此类异常信息

Caused by: reactor.netty.http.client.PrematureCloseException: Connection prematurely closed BEFORE response
2021-12-01 08:06:18.715 [reactor-http-epoll-1] WARN  r.n.http.client.HttpClientConnect -[id:9eb3d572-22, L:/10.2.1.2:47286 ! R:10.2.1.1/10.2.1.1:8030] The connection observed an error
reactor.netty.http.client.PrematureCloseException: Connection prematurely closed BEFORE response
2021-12-01 08:06:18.716 [reactor-http-epoll-1] INFO  d.c.b.a.s.services.StatusUpdater -Couldn't retrieve status for Instance(id=0b337b0012c5, version=19, registration=Registration(name=ORDER, managementUrl=http://10.2.1.1:8030/actuator, healthUrl=http://10.2.1.1:8030/actuator/health, serviceUrl=http://10.2.1.1:8030, source=discovery), registered=true, statusInfo=StatusInfo(status=UP, details={}), statusTimestamp=2021-11-30T17:05:18.806Z, info=Info(values={}), endpoints=Endpoints(endpoints={health=Endpoint(id=health, url=http://10.2.1.1:8030/actuator/health)}), buildVersion=null, tags=Tags(values={}))
org.springframework.web.reactive.function.client.WebClientRequestException: Connection prematurely closed BEFORE response; nested exception is reactor.netty.http.client.PrematureCloseException: Connection prematurely closed BEFORE response

然后分析大概是reactor.netty 配置问题导致。
先查看当前项目使用的组件版本：

Spring Boot version: 2.4.2
Reactor netty version: 1.0.3
spring-boot-admin version: 2.4.3

git hub上也已经关注了这个问题：
https://github.com/codecentric/spring-boot-admin/issues/1711

目前尝试的
解决方案1：
将reactor netty版本修改为0.9.10.RELEASE

   de.codecentric
   spring-boot-admin-starter-server
   
      
         io.projectreactor.netty
         reactor-netty
      
   


   io.projectreactor.netty
   reactor-netty
   0.9.10.RELEASE

注意：方案1经过测试，仍然会出现上面异常，故方案1不可解决。
解决方案2：
添加JVM启动参数，更改从连接池中取连接的策略，由FIFO变更为LIFO（reactor.netty.resources.ConnectionProvider），确保拿到的连接永远是最新的连接；

-Dreactor.netty.pool.leasingStrategy=lifo

注意：方案2经过测试，仍然会出现上面异常，故方案2不可解决。

配置如下：

spring:
	boot:
		admin:
			monitor:
				status-interval: 60000
				status-lifetime: 60000

现在在跟进github上原作者的相关动作。
https://github.com/codecentric/spring-boot-admin/issues/1711
https://github.com/reactor/reactor-netty/pull/1905

参考：
https://codecentric.github.io/spring-boot-admin
https://zhuanlan.zhihu.com/p/272902531
https://blog.csdn.net/yaomingyang/article/details/114330502