This page describes a singular cause for Out Of Memory Heap Space Errors. Refer to JIRA Crashes Due to OutOfMemoryError Java heap space for a general discussion.
JIRA crashes after running out of memory. Logs contain the error message OutOfMemory Errors.
Tomcat 5 caches JSP content. If JIRA is generating huge responses (eg. multi-megabyte Excel or RSS views), then these cached responses will quickly fill up memory and result in OutOfMemoryErrors.
Do not deploy multiple Atlassian applications in a single Tomcat container
Deploying multiple Atlassian applications in a single Tomcat container is not supported. We do not test this configuration and upgrading any of the applications (even for point releases) is likely to break it. There are also a number of known issues with this configuration (see this FAQ for more information).
We also strongly recommend not deploying multiple Atlassian applications to a single Tomcat container for a number of practical reasons. Firstly, you must shut down Tomcat to upgrade any application and secondly, if one application crashes, the other applications running in that Tomcat container will be inaccessible.
Finally, we recommend not deploying any other applications to the same Tomcat container that runs JIRA, especially if these other applications have large memory requirements or require additional libraries in Tomcat's