[
https://issues.apache.org/jira/browse/LOG4J2-570?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=13945757#comment-13945757
]
Scott commented on LOG4J2-570:
------------------------------
Sounds promising. Can you explain why 2 shutdown hooks are needed? Is there
some way tomcat (or servlet containers in general) can be shutdown where the
ServletContextListener contextDestroyed is not called for each listener, but
the Tomcat System.exit() event causes the additional shutdown hook to be
called? In the simple use cases (stopping/unloading/redeploying, using the
tomcat shutdown scripts, and even killing the Tomcat application from Visual
VM) the contextDestroyed methods are called (verified via log4j2 log file
output).
Using a weak reference will likely help for this use-case, but is there a
potential this will break other use-cases that are relying on a non-weak
pointer?
I created another issue for the JMX memory leak (LOG4J2-578) as per your
earlier suggestion.
> Memory Leak
> -----------
>
> Key: LOG4J2-570
> URL: https://issues.apache.org/jira/browse/LOG4J2-570
> Project: Log4j 2
> Issue Type: Bug
> Components: Core
> Affects Versions: 2.0-rc1
> Environment: Ubuntu 12.04
> Linux 3.2.0-58-generic x86_64 GNU/Linux
> 8 GB RAM
> java version "1.7.0_51"
> Java(TM) SE Runtime Environment (build 1.7.0_51-b13)
> Java HotSpot(TM) 64-Bit Server VM (build 24.51-b03, mixed mode)
> JAVA_OPTS=-Xmx1024m -Dsun.net.inetaddr.ttl=60
> -Dsun.net.inetaddr.negative.ttl=60 -Djava.net.preferIPv4Stack=true
> -XX:PermSize=128m -XX:MaxPermSize=256m -XX:+UseConcMarkSweepGC
> -XX:+CMSClassUnloadingEnabled
> <log4j.version>2.0-rc1</log4j.version>
> log4j-api
> log4j-core
> log4j-jcl
> Spring webmvc 4.0.2.RELEASE application (simple hello world) deployed in
> tomcat7.0.52 container.
> Reporter: Scott
> Assignee: Matt Sicker
> Priority: Blocker
> Labels: memory_leak
> Fix For: 2.0-rc2
>
> Attachments: spring_log4j2_memory_leak.tbz2
>
>
> Dynamically loading a JAR that uses log4j2 results in a memory leak when the
> JAR is unloaded. This can be observed by deploying a web application to
> tomcat7 and exercising the stop, undeploy, or redeploy actions. The memory
> leak is believed to be caused by log4j for the following reasons:
> 1)Heap Dump reveals the classloader instance responsible for the WAR plugin
> (of type org.apache.catalina.loader.WebappClassLoader) has 2 non weak/soft
> reference which are of type
> (org.apache.logging.log4j.core.LoggerContext$ShutdownThread) and
> (org.apache.logging.log4j.core.jmx.LoggerContextAdmin) after the WAR has been
> stopped or undeployed.
> 2)Using SLF4J (slf4j-api, jcl-over-slf4j) to logback-classic logging output
> is equivalent but all memory is gc as expected (the
> org.apache.catalina.loader.WebappClassLoader which loaded the WAR is no
> longer referenced by any hard references)
> 3)Using the SLF4J NOP logger implementation all memory is gc as expected (the
> org.apache.catalina.loader.WebappClassLoader which loaded the WAR is no
> longer referenced by any hard references)
> This may not be unique to 2.0rc-1 and I have seen similar behavior in
> previous 2.0 beta releases.
> This is reproducible with a very simple spring hello world application. Code
> and/or heap dumps can be provided upon request.
--
This message was sent by Atlassian JIRA
(v6.2#6252)
---------------------------------------------------------------------
To unsubscribe, e-mail: log4j-dev-unsubscr...@logging.apache.org
For additional commands, e-mail: log4j-dev-h...@logging.apache.org
