Tomcat 7.0.23 and 7.0.27 include a feature in the Web Application Manager that allows you to search for memory leaks. When OpenMRS 1.9.0 is undeployed, and you click to Find Leaks, it reports the following...
The following web applications were stopped (reloaded, undeployed), but their
classes from previous runs are still loaded in memory, thus causing a memory
leak (use a profiler to confirm):