FingerprintCleanupThread currently either deletes the whole record (when none of the information in the record is in use anywhere at all) or not touch it at all.

This means that some fingerprints (such as one for maven-compiler-plugin that every Maven build likely uses) will remain there forever with lots of build records and jobs that are long gone.

The garbage collection algorithm should probably be more aggressive and remove references to builds and jobs that no longer exist when it can.