Spring Cache's in Stash and Bitbucket DC versions up to and including 4.7.0 are backed by Hazelcast IMap's internally. In some scenarios, this can cause cache accesses from one cluster node to block waiting for another cluster node, which in the event of OS or JVM issues (e.g., excessive GC pauses) may be slow or unresponsive.

In Bitbucket Data Center 4.8.0 and higher, this has been replaced with hybrid-mode atlassian-cache Cache's which do not block on other cluster nodes even if they are affected by OS or JVM issues.