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Pentaho Documentation

Tomcat Logs Report Memory Leaks

When shutting down Tomcat, you may see some SEVERE-level warnings in the log file similar to these:

Dec 17, 2010 10:18:19 AM org.apache.catalina.loader.WebappClassLoader clearReferencesJdbc
SEVERE: The web application [/pentaho] registered the JBDC driver [mondrian.olap4j.MondrianOlap4jDriver] but failed to unregister it when the web application was stopped. To prevent a memory leak, the JDBC Driver has been forcibly unregistered.
Dec 17, 2010 10:18:19 AM org.apache.catalina.loader.WebappClassLoader clearReferencesThreads
SEVERE: The web application [/pentaho] appears to have started a thread named [HSQLDB Timer @49cf9f] but has failed to stop it. This is very likely to create a memory leak.
Dec 17, 2010 10:18:19 AM org.apache.catalina.loader.WebappClassLoader clearReferencesThreads
SEVERE: The web application [/pentaho] appears to have started a thread named [MySQL Statement Cancellation Timer] but has failed to stop it. This is very likely to create a memory leak.
Dec 17, 2010 10:18:19 AM org.apache.catalina.loader.WebappClassLoader clearThreadLocalMap
SEVERE: The web application [/pentaho] created a ThreadLocal with key of type [java.lang.InheritableThreadLocal] (value [java.lang.InheritableThreadLocal@a1320e]) and a value of type [org.pentaho.platform.engine.security.session.TrustedSystemStartupSession] (value [org.pentaho.platform.engine.security.session.TrustedSystemStartupSession@111089b]) but failed to remove it when the web application was stopped. This is very likely to create a memory leak.

These warnings are nothing to be concerned about when shutting down the Tomcat server, since they report problems with processes that are immanently being killed. However, they can have significance if you are only restarting or redeploying the Pentaho BA Server or DI Server Web applications. To avoid any memory leak problems in redeployment, you should restart Tomcat instead of redeploying or restarting the Web application with a live server.