[LOG4J2-1618] ClassCastException at shutdown with JUL: casting SimpleLogger to Logger

• Type: Bug
• Status: Closed
• Priority: Major
• Resolution: Fixed
• Affects Version/s: 2.6.2, 2.7
• Fix Version/s: 2.7
• Component/s: Core
• Flags: Important
• Assignee: Remko Popma
• Reporter: Raman Gupta
• Created: 28/Sep/16 21:06
• Updated: 01/Oct/16 13:24
• Resolved: 01/Oct/16 11:21

Description

Apparently the fix for https://issues.apache.org/jira/browse/LOG4J2-1222 is causing a new issue when log4j-jul is enabled:

2016-09-28 16:54:29,300 Thread-1 WARN Unable to register Log4j shutdown hook because JVM is shutting down. Using SimpleLogger
Exception in thread "Thread-1" java.lang.ExceptionInInitializerError
	at io.grpc.internal.SharedResourceHolder.releaseInternal(SharedResourceHolder.java:152)
	at io.grpc.internal.SharedResourceHolder.release(SharedResourceHolder.java:112)
	at io.grpc.internal.ServerImpl.shutdown(ServerImpl.java:182)
	at io.grpc.internal.ServerImpl.shutdown(ServerImpl.java:79)
	at com.rocketraman.Foo.stop(Foo.kt:39)
	at java.lang.Thread.run(Thread.java:745)
Caused by: java.lang.ClassCastException: org.apache.logging.log4j.simple.SimpleLogger cannot be cast to org.apache.logging.log4j.core.Logger
	at org.apache.logging.log4j.jul.CoreLoggerAdapter.newLogger(CoreLoggerAdapter.java:37)
	at org.apache.logging.log4j.jul.CoreLoggerAdapter.newLogger(CoreLoggerAdapter.java:31)
	at org.apache.logging.log4j.spi.AbstractLoggerAdapter.getLogger(AbstractLoggerAdapter.java:48)
	at org.apache.logging.log4j.jul.LogManager.getLogger(LogManager.java:89)
	at java.util.logging.LogManager.demandLogger(LogManager.java:551)
	at java.util.logging.Logger.demandLogger(Logger.java:455)
	at java.util.logging.Logger.getLogger(Logger.java:502)
	at io.grpc.internal.LogExceptionRunnable.<clinit>(LogExceptionRunnable.java:47)
	... 7 more

If I follow the chain of inheritance of `SimpleLogger`, the top-level interface is `org.apache.logging.log4j.Logger` from the -api jar, not `org.apache.logging.log4j.core.Logger` from the -core jar.

Issue Links

• is broken by: LOG4J2-1222 Initializing Logger during JVM shutdown fails with FATAL error