Another issue where an undeployed WAR's classloader is not GCed.
It looks to me like the TomcatJAASRealm (its name is "DefaultJAASRealm") is a standard realm that is used by all WARs without explicit configuration. Setting the realm of a GeronimoStandardContext makes the context store a reference to its realm AND makes the realm store a reference to the context (see org.apache.catalina.core.ContainerBase#setRealm() which GeronimoStandardContext inherits). Thus, the default realm's reference is always directed to the context of the WAR deployed most recently. This reference keeps the context from being GCed even if the corresponding WAR has been undeployed in the meantime.