We have a large jira instance (>200k stories)

We have 45k users

We CARE about performance of jira, and optimising crowd integration has made a decent impact.

We care aboure the file:
com.atlassian.crowd.integration.service.cache.CachingGroupMembershipManager

specifically the method
public boolean isMember(String userName, String groupName) throws RemoteException, InvalidAuthorizationTokenException

is very immature. There is even a ToDo in the source code to say unoptimised.

Optimising this method resulted in >50% of our calls to the crowd remote service being rendered useless.

Attached is a version currently undergoing testing