Currently Tomcat re-use their output buffers (ostensibly for performance), but if you serve a large amount of HTML (say 10MB) the buffers sit around forever, and don't get cleaned up. Note that Orion also has this problem. There is a flag "org.apache.jasper.runtime.BodyContentImpl.LIMIT_BUFFER" that you can set which limits this. We should set it in the standalone versions, and also let people to know to set it in their own Tomcat instances. If you are using Tomcat you must set the following in your java options: Note that this option is only available for Tomcat 5.5.15 and above. All earlier Tomcat 5 builds are susceptible to this problem and should be upgraded. In JIRA Standalone this is set in the bin/setenv.sh or bin/setenv.bat by default. If you do not set this you will get OutOfMemoryErrors.