本文主要介绍如何Spring Boot Admin，以此监控Springboot应用

搭建Admin Server

引入依赖

<?xml version="1.0" encoding="UTF-8"?>
<project xmlns="http://maven.apache.org/POM/4.0.0"
         xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
         xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/xsd/maven-4.0.0.xsd">
    <parent>
        <artifactId>spring-learn</artifactId>
        <groupId>org.ym</groupId>
        <version>1.0-SNAPSHOT</version>
    </parent>
    <modelVersion>4.0.0</modelVersion>

    <artifactId>learn-monitor</artifactId>

    <properties>
        <maven.compiler.source>8</maven.compiler.source>
        <maven.compiler.target>8</maven.compiler.target>
    </properties>

    <dependencies>
        <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-starter-web</artifactId>
        </dependency>

        <dependency>
            <groupId>de.codecentric</groupId>
            <artifactId>spring-boot-admin-starter-server</artifactId>
            <exclusions>
                <exclusion>
                    <groupId>io.projectreactor.netty</groupId>
                    <artifactId>reactor-netty</artifactId>
                </exclusion>
            </exclusions>
        </dependency>

        <dependency>
            <groupId>io.projectreactor.netty</groupId>
            <artifactId>reactor-netty</artifactId>
        </dependency>

        <!--健康检查-->
        <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-starter-actuator</artifactId>
        </dependency>

        <!--解决启动时报dns native错误-->
        <dependency>
            <groupId>io.netty</groupId>
            <artifactId>netty-resolver-dns-native-macos</artifactId>
            <classifier>osx-aarch_64</classifier>
        </dependency>
    </dependencies>

</project>

Admin Server启动类

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

application.yml配置

server:
  port: 9401
spring:
  application:
    name: learn-monitor
  boot:
    admin:
      monitor:
        default-timeout: 30000

测试

http://127.0.0.1:9401/applications

搭建Admin Client

引入依赖

<!--admin-->
<dependency>
    <groupId>de.codecentric</groupId>
    <artifactId>spring-boot-admin-starter-client</artifactId>
</dependency>

application.yml配置

spring:
  application:
    name: learn-test
  mvc:
    pathmatch:
      matching-strategy: ant_path_matcher
  boot:
    admin:
      client:
        url: http://localhost:9401 #配置admin-server地址
management:
  endpoints:
    web:
      exposure:
        include: '*'
  endpoint:
    health:
      show-details: always

存在问题

java.util.concurrent.TimeoutException: Did not observe any item or terminal signal within 10000ms in 'map' (and no fallback has been configured)
	at reactor.core.publisher.FluxTimeout$TimeoutMainSubscriber.handleTimeout(FluxTimeout.java:295) ~[reactor-core-3.4.21.jar:3.4.21]
	Suppressed: reactor.core.publisher.FluxOnAssembly$OnAssemblyException: 
Error has been observed at the following site(s):
	*__checkpoint ⇢ Request to GET health [DefaultWebClient]
Original Stack Trace:
		at reactor.core.publisher.FluxTimeout$TimeoutMainSubscriber.handleTimeout(FluxTimeout.java:295) ~[reactor-core-3.4.21.jar:3.4.21]
		at reactor.core.publisher.FluxTimeout$TimeoutMainSubscriber.doTimeout(FluxTimeout.java:280) ~[reactor-core-3.4.21.jar:3.4.21]
		at reactor.core.publisher.FluxTimeout$TimeoutTimeoutSubscriber.onNext(FluxTimeout.java:419) ~[reactor-core-3.4.21.jar:3.4.21]
		at reactor.core.publisher.FluxOnErrorResume$ResumeSubscriber.onNext(FluxOnErrorResume.java:79) ~[reactor-core-3.4.21.jar:3.4.21]
		at reactor.core.publisher.MonoDelay$MonoDelayRunnable.propagateDelay(MonoDelay.java:271) ~[reactor-core-3.4.21.jar:3.4.21]
		at reactor.core.publisher.MonoDelay$MonoDelayRunnable.run(MonoDelay.java:286) ~[reactor-core-3.4.21.jar:3.4.21]
		at reactor.core.scheduler.SchedulerTask.call(SchedulerTask.java:68) ~[reactor-core-3.4.21.jar:3.4.21]
		at reactor.core.scheduler.SchedulerTask.call(SchedulerTask.java:28) ~[reactor-core-3.4.21.jar:3.4.21]
		at java.util.concurrent.FutureTask.run(FutureTask.java:266) ~[na:1.8.0_322]
		at java.util.concurrent.ScheduledThreadPoolExecutor$ScheduledFutureTask.access$201(ScheduledThreadPoolExecutor.java:180) ~[na:1.8.0_322]
		at java.util.concurrent.ScheduledThreadPoolExecutor$ScheduledFutureTask.run(ScheduledThreadPoolExecutor.java:293) ~[na:1.8.0_322]
		at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1149) ~[na:1.8.0_322]
		at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:624) ~[na:1.8.0_322]
		at java.lang.Thread.run(Thread.java:750) ~[na:1.8.0_322]

可能的解决方法：

1. 在application.yml中修改时间，default-timeout: 30000
2. 修改springboot-admin版本
3. 关闭redis，email等服务

management:
  endpoints:
    web:
      exposure:
        include: '*'
  endpoint:
    health:
      show-details: always
  health:
    redis:
      enabled: false
    mail:
      enabled: false