On Shutwown and Redeploy I often get these errors or OOM.

[Mark Diskin]

05-Apr2012 12:17:46.806 INFO org.apache.catalina.startup.HostConfig.checkResources Undeploying context [/jira]
05-Apr-2012 12:17:53.071 SEVERE org.apache.catalina.loader.WebappClassLoader.clearReferencesThreads The web application [/jira] appears to have started a thread named [[Pool-Cleaner]:Tomcat Connection Pool[1-1668423202]] but has failed to stop it. This is very likely to create a memory leak.
05-Apr-2012 12:17:53.071 SEVERE org.apache.catalina.loader.WebappClassLoader.clearReferencesThreads The web application [/jira] appears to have started a thread named [JonasBatch] but has failed to stop it. This is very likely to create a memory leak.
05-Apr-2012 12:17:53.071 SEVERE org.apache.catalina.loader.WebappClassLoader.clearReferencesThreads The web application [/jira] appears to have started a thread named [JonasClock] but has failed to stop it. This is very likely to create a memory leak.
05-Apr-2012 12:17:53.071 SEVERE org.apache.catalina.loader.WebappClassLoader.clearReferencesThreads The web application [/jira] appears to have started a thread named [MultiThreadedHttpConnectionManager cleanup] but has failed to stop it. This is very likely to create a memory leak.
05-Apr-2012 12:17:53.071 SEVERE org.apache.catalina.loader.WebappClassLoader.clearThreadLocalMap The web application [/jira] created a ThreadLocal with key of type [com.atlassian.jira.util.ImportUtils$2] (value [com.atlassian.jira.util.ImportUtils$2@3f9e4e04]) and a value of type [java.lang.Boolean] (value [true]) but failed to remove it when the web application was stopped. This is very likely to create a memory leak.
05-Apr-2012 12:17:53.071 SEVERE org.apache.catalina.loader.WebappClassLoader.clearThreadLocalMap The web application [/jira] created a ThreadLocal with key of type [com.atlassian.jira.util.ImportUtils$3] (value [com.atlassian.jira.util.ImportUtils$3@3214093d]) and a value of type [java.lang.Boolean] (value [true]) but failed to remove it when the web application was stopped. This is very likely to create a memory leak.
05-Apr-2012 12:17:53.071 SEVERE org.apache.catalina.loader.WebappClassLoader.clearThreadLocalMap The web application [/jira] created a ThreadLocal with key of type [java.lang.ThreadLocal] (value [java.lang.ThreadLocal@416a9d7a]) and a value of type [org.dom4j.DocumentFactory] (value [org.dom4j.DocumentFactory@3e88d623]) but failed to remove it when the web application was stopped. This is very likely to create a memory leak.
05-Apr-2012 12:17:53.071 SEVERE org.apache.catalina.loader.WebappClassLoader.clearThreadLocalMap The web application [/jira] created a ThreadLocal with key of type [com.atlassian.instrumentation.operations.ThreadLocalOpTimerFactory$1] (value [com.atlassian.instrumentation.operations.ThreadLocalOpTimerFactory$1@9a2b3e8]) and a value of type [com.atlassian.instrumentation.operations.registry.OpRegistry] (value [com.atlassian.instrumentation.operations.registry.OpRegistry@18d14949 {db.reads=name=db.reads; inv=1779; ms=4667; cpu=0; rss=0;, db.conns=name=db.conns; inv=1831; ms=7753; cpu=0; rss=0;, db.writes=name=db.writes; inv=107; ms=251; cpu=0; rss=0;}]) but failed to remove it when the web application was stopped. This is very likely to create a memory leak.
05-Apr-2012 12:17:53.071 SEVERE org.apache.catalina.loader.WebappClassLoader.clearThreadLocalMap The web application [/jira] created a ThreadLocal with key of type [java.lang.ThreadLocal] (value [java.lang.ThreadLocal@54226459]) and a value of type [com.atlassian.jira.issue.index.SearcherCache] (value [com.atlassian.jira.issue.index.SearcherCache@1dea3a36]) but failed to remove it when the web application was stopped. This is very likely to create a memory leak.
05-Apr-2012 12:17:53.071 SEVERE org.apache.catalina.loader.WebappClassLoader.clearThreadLocalMap The web application [/jira] created a ThreadLocal with key of type [com.atlassian.jira.util.ImportUtils$1] (value [com.atlassian.jira.util.ImportUtils$1@7c93be91]) and a value of type [java.lang.Boolean] (value [false]) but failed to remove it when the web application was stopped. This is very likely to create a memory leak.
05-Apr-2012 12:17:53.071 SEVERE org.apache.catalina.loader.WebappClassLoader.clearThreadLocalMap The web application [/jira] created a ThreadLocal with key of type [com.atlassian.jira.util.ImportUtils$2] (value [com.atlassian.jira.util.ImportUtils$2@3f9e4e04]) and a value of type [java.lang.Boolean] (value [true]) but failed to remove it when the web application was stopped. This is very likely to create a memory leak.
05-Apr-2012 12:17:53.071 SEVERE org.apache.catalina.loader.WebappClassLoader.clearThreadLocalMap The web application [/jira] created a ThreadLocal with key of type [java.lang.ThreadLocal] (value [java.lang.ThreadLocal@54226459]) and a value of type [com.atlassian.jira.issue.index.SearcherCache] (value [com.atlassian.jira.issue.index.SearcherCache@47c4617c]) but failed to remove it when the web application was stopped. This is very likely to create a memory leak.
05-Apr-2012 12:17:53.071 SEVERE org.apache.catalina.loader.WebappClassLoader.clearThreadLocalMap The web application [/jira] created a ThreadLocal with key of type [com.atlassian.jira.util.ImportUtils$3] (value [com.atlassian.jira.util.ImportUtils$3@3214093d]) and a value of type [java.lang.Boolean] (value [true]) but failed to remove it when the web application was stopped. This is very likely to create a memory leak.
05-Apr-2012 12:17:53.071 SEVERE org.apache.catalina.loader.WebappClassLoader.clearThreadLocalMap The web application [/jira] created a ThreadLocal with key of type [com.atlassian.jira.util.ImportUtils$1] (value [com.atlassian.jira.util.ImportUtils$1@7c93be91]) and a value of type [java.lang.Boolean] (value [false]) but failed to remove it when the web application was stopped. This is very likely to create a memory leak.

Tomcat is leak detect errors - any plans to address these and also support tomcat 7?

Check out http://wiki.apache.org/tomcat/MemoryLeakProtection

Thanks

Mark

[Radek Kantor]

Hi, Atlassian looks like not interested in this common and well known Tomcat6 bug although Tomcat6 is main supported server. Priority to fix this memory leaks is low and probably will be solved by migrating on Tomcat7 in the future.

https://answers.atlassian.com/questions/38047/tomcat-6-threadlocal-memory-leak