Application with log4j causes perm gen leak across redeployments

Environment

• JBoss Enterprise Application Platform (EAP)
• log4j

Issue

• Our application has log4j bundled in it. After redeploying this app several times, we hit a perm gen OOME. The heap dump shows many of the application classloaders persisted by a still running log4j PropertyWatchdog or FileWatchdog thread.

Resolution

• The thread would be started due to a call to Content from logging.apache.org is not included.PropertyConfigurator.configureAndWatch so its use should be avoided. Just call configure instead.
• If using Spring, do not set the log4jRefreshInterval parameter

Root Cause

• log4j does not offer a way to shutdown PropertyWatchdog or FileWatchdog threads
• Content from bz.apache.org is not included.BZ-4913

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