The heap size of the FishEye Java Virtual Machine is controlled by the FISHEYE_OPTS environment variable. The best heap size to use is dependent on a number of factors including:

• The SCM system being used. Subversion scanning typically uses more memory than CVS, for example.
• The complexity of operations in the repository. Processing changesets which affect many files will use more memory
• The amount of physical RAM in the system. If the Java heap is too large, it may induce swapping which will impact performance

FishEye will reserve a portion of the available heap for caching of database data, so, in general, the more memory you can supply, the better.

If you do run into OutOfMemory errors, you will need to increase the heap size and restart FishEye

For Subversion respositories, it is also possible to reduce FishEye's memory footprint by reducing the BlockSize parameter