On a context reload, Tomcat seems to check whether all resources have been released correctly.

Using Tomcat 6.0.24, context reloading causes the following log entries to appear on the console:

    Jun 23, 2010 9:19:33 AM org.apache.catalina.core.StandardContext reload
INFO: Reloading this Context has started
Jun 23, 2010 9:19:33 AM org.apache.catalina.loader.WebappClassLoader clearReferencesJdbc
SEVERE: A web application registered the JBDC driver [com.mysql.jdbc.Driver] but failed to unregister it when the web application was stopped. To prevent a memory leak, the JDBC Driver has been forcibly unregistered.
Jun 23, 2010 9:19:33 AM org.apache.catalina.loader.WebappClassLoader clearReferencesJdbc
SEVERE: A web application registered the JBDC driver [org.sqlite.JDBC] but failed to unregister it when the web application was stopped. To prevent a memory leak, the JDBC Driver has been forcibly unregistered.
Jun 23, 2010 9:19:33 AM org.apache.catalina.loader.WebappClassLoader clearReferencesThreads
SEVERE: A web application appears to have started a thread named [Timer-0] but has failed to stop it. This is very likely to create a memory leak.
Jun 23, 2010 9:19:33 AM org.apache.catalina.loader.WebappClassLoader clearReferencesThreads
SEVERE: A web application appears to have started a thread named [com.mchange.v2.async.ThreadPoolAsynchronousRunner$PoolThread-#0] but has failed to stop it. This is very likely to create a memory leak.
Jun 23, 2010 9:19:33 AM org.apache.catalina.loader.WebappClassLoader clearReferencesThreads
SEVERE: A web application appears to have started a thread named [com.mchange.v2.async.ThreadPoolAsynchronousRunner$PoolThread-#1] but has failed to stop it. This is very likely to create a memory leak.
Jun 23, 2010 9:19:33 AM org.apache.catalina.loader.WebappClassLoader clearReferencesThreads
SEVERE: A web application appears to have started a thread named [com.mchange.v2.async.ThreadPoolAsynchronousRunner$PoolThread-#2] but has failed to stop it. This is very likely to create a memory leak.
Jun 23, 2010 9:19:33 AM org.apache.catalina.loader.WebappClassLoader clearReferencesThreads
SEVERE: A web application appears to have started a thread named [Store org.hibernate.cache.UpdateTimestampsCache Spool Thread] but has failed to stop it. This is very likely to create a memory leak.
Jun 23, 2010 9:19:33 AM org.apache.catalina.loader.WebappClassLoader clearReferencesThreads
SEVERE: A web application appears to have started a thread named [Store org.hibernate.cache.UpdateTimestampsCache Expiry Thread] but has failed to stop it. This is very likely to create a memory leak.
Jun 23, 2010 9:19:33 AM org.apache.catalina.loader.WebappClassLoader clearReferencesThreads
SEVERE: A web application appears to have started a thread named [Store org.hibernate.cache.StandardQueryCache Spool Thread] but has failed to stop it. This is very likely to create a memory leak.
Jun 23, 2010 9:19:33 AM org.apache.catalina.loader.WebappClassLoader clearReferencesThreads
SEVERE: A web application appears to have started a thread named [Store org.hibernate.cache.StandardQueryCache Expiry Thread] but has failed to stop it. This is very likely to create a memory leak.

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Submitted by Nathan Bruning on 23 June 2010 at 09:25

Fixed by https://yellowgrass.org/issue/WebDSL/317