I simply start up a zookeeper server (3.4.6) with using the org.apache.zookeeper.server.ZooKeeperServerMain.runFromConfig(ServerConfig)
method, then I try to shut it down. During shutdown I get this:
11:43:11,176 WARN {main} [org.apache.zookeeper.jmx.MBeanRegistry] Failed to unregister MBean InMemoryDataTree
11:43:11,176 WARN {main} [org.apache.zookeeper.jmx.MBeanRegistry] Error during unregister
javax.management.InstanceNotFoundException: org.apache.ZooKeeperService:name0=StandaloneServer_port-1,name1=InMemoryDataTree
at com.sun.jmx.interceptor.DefaultMBeanServerInterceptor.getMBean(DefaultMBeanServerInterceptor.java:1095)
at com.sun.jmx.interceptor.DefaultMBeanServerInterceptor.exclusiveUnregisterMBean(DefaultMBeanServerInterceptor.java:427)
at com.sun.jmx.interceptor.DefaultMBeanServerInterceptor.unregisterMBean(DefaultMBeanServerInterceptor.java:415)
at com.sun.jmx.mbeanserver.JmxMBeanServer.unregisterMBean(JmxMBeanServer.java:546)
at org.apache.zookeeper.jmx.MBeanRegistry.unregister(MBeanRegistry.java:115)
at org.apache.zookeeper.jmx.MBeanRegistry.unregister(MBeanRegistry.java:132)
at org.apache.zookeeper.server.ZooKeeperServer.unregisterJMX(ZooKeeperServer.java:465)
at org.apache.zookeeper.server.ZooKeeperServer.shutdown(ZooKeeperServer.java:458)
at org.apache.zookeeper.server.NIOServerCnxnFactory.shutdown(NIOServerCnxnFactory.java:271)
at org.apache.zookeeper.server.ZooKeeperServerMain.shutdown(ZooKeeperServerMain.java:132)
...
I have unfortunately no idea what the error Failed to unregister MBean InMemoryDataTree means. I did not find anything with search engines apart from logs from some project builds. I could read the code, but it would take obviously a lot of time to understand that.
Do I have to change something in my startup process to get rid of this, or is this completely normal?