When starting a Spring Boot Application (Spring Boot v2.35) in a Docker container using HikariCP (v3.4.5) the following warning appears in logs:
Picked up JAVA_TOOL_OPTIONS: ... -Dcom.sun.management.jmxremote -Dcom.sun.management.jmxremote.ssl=false -Djava.rmi.server.hostname=<dockerhostname> -Dcom.sun.management.jmxremote.port=3181 -Dcom.sun.management.jmxremote.rmi.port=3181 -Dcom.sun.management.jmxremote.authenticate=false ....
...
2021-06-08 07:22:07.781 INFO 1 --- [ main] com.zaxxer.hikari.HikariDataSource : HikariPool-1 - Starting...
2021-06-08 07:22:08.077 WARN 1 --- [MI TCP Accept-0] sun.rmi.transport.tcp : RMI TCP Accept-0: accept loop for ServerSocket[addr=0.0.0.0/0.0.0.0,localport=41775] throws
java.net.SocketTimeoutException: Accept timed out
at java.base/java.net.PlainSocketImpl.socketAccept(Native Method)
at java.base/java.net.AbstractPlainSocketImpl.accept(AbstractPlainSocketImpl.java:458)
at java.base/java.net.ServerSocket.implAccept(ServerSocket.java:565)
at java.base/java.net.ServerSocket.accept(ServerSocket.java:533)
at jdk.management.agent/sun.management.jmxremote.LocalRMIServerSocketFactory$1.accept(LocalRMIServerSocketFactory.java:52)
at java.rmi/sun.rmi.transport.tcp.TCPTransport$AcceptLoop.executeAcceptLoop(TCPTransport.java:394)
at java.rmi/sun.rmi.transport.tcp.TCPTransport$AcceptLoop.run(TCPTransport.java:366)
at java.base/java.lang.Thread.run(Thread.java:834)
2021-06-08 07:22:08.079 WARN 1 --- [TCP Accept-3181] sun.rmi.transport.tcp : RMI TCP Accept-3181: accept loop for ServerSocket[addr=0.0.0.0/0.0.0.0,localport=3181] throws
java.net.SocketTimeoutException: Accept timed out
at java.base/java.net.PlainSocketImpl.socketAccept(Native Method)
at java.base/java.net.AbstractPlainSocketImpl.accept(AbstractPlainSocketImpl.java:458)
at java.base/java.net.ServerSocket.implAccept(ServerSocket.java:565)
at java.base/java.net.ServerSocket.accept(ServerSocket.java:533)
at java.rmi/sun.rmi.transport.tcp.TCPTransport$AcceptLoop.executeAcceptLoop(TCPTransport.java:394)
at java.rmi/sun.rmi.transport.tcp.TCPTransport$AcceptLoop.run(TCPTransport.java:366)
at java.base/java.lang.Thread.run(Thread.java:834)
2021-06-08 07:22:08.273 INFO 1 --- [ main] com.zaxxer.hikari.HikariDataSource : HikariPool-1 - Start completed.
The application configuration contains
spring:
datasource:
hikari:
register-mbeans: true
jmx:
enabled: true
The later JMX access via VisualVM works, so the warnings seem to have no effect.
I guessed it could be an initialization problem, so I set a dependency from DataSource-Bean to the Micrometer MeterRegistry-Bean explicitly. But that doesn't help.
What is the cause for the warnings? And how to get rid of them?