添加javaagent后Tomcat无法关闭：-javaagent处理失败问题求助

关键信息 #

• Tomcat的catalina.bat路径：E:\work-tomcat\apache-tomcat-9.0.71\bin
• jmx_prometheus_javaagent-0.17.2.jar路径：F:/work-Grafana/jmx_prometheus_javaagent-0.17.2.jar
• catalina.bat修改内容：

  set "JAVA_OPTS=%JAVA_OPTS% %JSSE_OPTS% -javaagent:F:/work-Grafana/jmx_prometheus_javaagent-0.17.2.jar=2023:F:/work-Grafana/prometheus-2.42.0.windows-amd64/jmx-exporter.yaml"
  

• Prometheus配置（prometheus.yml）：

  job_name: "tomcat"
  static_configs:
  - targets: ["127.0.0.1:2023"]
  

• 启动状态：Tomcat与Prometheus启动正常，监控功能正常
• 关闭时报错：

  E:\work-tomcat\apache-tomcat-9.0.71\bin>shutdown.bat
  Using CATALINA_BASE:   "E:\work-tomcat\apache-tomcat-9.0.71"
  Using CATALINA_HOME:   "E:\work-tomcat\apache-tomcat-9.0.71"
  Using CATALINA_TMPDIR: "E:\work-tomcat\apache-tomcat-9.0.71\temp"
  Using JRE_HOME:        "C:\Program Files\Java\jdk1.8.0_201"
  Using CLASSPATH:       "E:\work-tomcat\apache-tomcat-9.0.71\bin\bootstrap.jar;E:\work-tomcat\apache-tomcat-9.0.71\bin\tomcat-juli.jar"
  Using CATALINA_OPTS:   ""
  Exception in thread "main" java.lang.reflect.InvocationTargetException
      at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
      at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:62)
      at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
      at java.lang.reflect.Method.invoke(Method.java:498)
      at sun.instrument.InstrumentationImpl.loadClassAndStartAgent(InstrumentationImpl.java:386)
      at sun.instrument.InstrumentationImpl.loadClassAndCallPremain(InstrumentationImpl.java:401)
  Caused by: java.net.BindException: Address already in use: bind
      at sun.nio.ch.Net.bind0(Native Method)
      at sun.nio.ch.Net.bind(Net.java:433)
      at sun.nio.ch.Net.bind(Net.java:425)
      at sun.nio.ch.ServerSocketChannelImpl.bind(ServerSocketChannelImpl.java:223)
      at sun.nio.ch.ServerSocketAdaptor.bind(ServerSocketAdaptor.java:74)
      at sun.net.httpserver.ServerImpl.<init>(ServerImpl.java:100)
      at sun.net.httpserver.HttpServerImpl.<init>(HttpServerImpl.java:50)
      at sun.net.httpserver.DefaultHttpServerProvider.createHttpServer(DefaultHttpServerProvider.java:35)
      at com.sun.net.httpserver.HttpServer.create(HttpServer.java:130)
      at io.prometheus.jmx.shaded.io.prometheus.client.exporter.HTTPServer.<init>(HTTPServer.java:396)
      at io.prometheus.jmx.JavaAgent.premain(JavaAgent.java:31)
      ... 6 more
  FATAL ERROR in native method: processing of -javaagent failed
  

问题原因 #

shutdown.bat执行时会继承JAVA_OPTS配置，尝试加载jmx_prometheus_javaagent并绑定2023端口，但此时Tomcat主进程已经占用了该端口，导致端口绑定失败，最终抛出错误。

解决方案 #

将javaagent的配置从JAVA_OPTS迁移到CATALINA_OPTS中。CATALINA_OPTS仅作用于Tomcat的主服务进程，shutdown.bat不会读取该变量，因此不会重复加载agent和绑定端口。

修改catalina.bat中的配置行：

set "CATALINA_OPTS=%CATALINA_OPTS% %JSSE_OPTS% -javaagent:F:/work-Grafana/jmx_prometheus_javaagent-0.17.2.jar=2023:F:/work-Grafana/prometheus-2.42.0.windows-amd64/jmx-exporter.yaml"

修改完成后重启Tomcat，之后执行shutdown.bat即可正常关闭服务。

内容的提问来源于stack exchange，提问作者SleepingBug