[LOG4J2-3121] log4j2 config modified at run-time may trigger incomplete MBean re-initialization due to InstanceAlreadyExistsException

• Type: Bug
• Status: Open
• Priority: Major
• Resolution: Unresolved
• Affects Version/s: 2.14.1
• Component/s: Core
• Assignee: Unassigned
• Reporter: Markus Spann
• Created: 09/Jul/21 13:51
• Updated: 11/Jul/21 12:12

Description

We occasionally encounter an InstanceAlreadyExistsException during log4j2 reconfiguration after update to the configuration file at run-time. This causes the MBean initialization to be incomplete.

The exception can be suppressed by checking whether the MBean is registered and de-registering it first. I will provide a pull request.

2021-07-09 14:37:37,961 Log4j2-TF-1-ConfiguratonFileWatcher-3 ERROR Could not register mbeans javax.management.InstanceAlreadyExistsException: org.apache.logging.log4j2:type=5c29bfd
 at java.management/com.sun.jmx.mbeanserver.Repository.addMBean(Repository.java:436)
 at java.management/com.sun.jmx.interceptor.DefaultMBeanServerInterceptor.registerWithRepository(DefaultMBeanServerInterceptor.java:1855)
 at java.management/com.sun.jmx.interceptor.DefaultMBeanServerInterceptor.registerDynamicMBean(DefaultMBeanServerInterceptor.java:955)
 at java.management/com.sun.jmx.interceptor.DefaultMBeanServerInterceptor.registerObject(DefaultMBeanServerInterceptor.java:890)
 at java.management/com.sun.jmx.interceptor.DefaultMBeanServerInterceptor.registerMBean(DefaultMBeanServerInterceptor.java:320)
 at java.management/com.sun.jmx.mbeanserver.JmxMBeanServer.registerMBean(JmxMBeanServer.java:522)
 at org.apache.logging.log4j.core.jmx.Server.register(Server.java:393)
 at org.apache.logging.log4j.core.jmx.Server.reregisterMBeansAfterReconfigure(Server.java:168)
 at org.apache.logging.log4j.core.jmx.Server.reregisterMBeansAfterReconfigure(Server.java:141)
 at org.apache.logging.log4j.core.LoggerContext.setConfiguration(LoggerContext.java:638)
 at org.apache.logging.log4j.core.LoggerContext.onChange(LoggerContext.java:763)
 at org.apache.logging.log4j.core.util.AbstractWatcher$ReconfigurationRunnable.run(AbstractWatcher.java:93)
 at java.base/java.lang.Thread.run(Thread.java:834)

Issue Links

• links to: GitHub Pull Request #547