Running Crowd integrated apps with Crowd offline

Question

Currently many of the Atlassian products will keep a sync of the Crowd directory locally to their application and will sync periodically with Crowd for instance this is how the User Directory is configured within Stash.

If Crowd goes down for any particular reason, should Stash continue to function properly or will it as well go into an unavailable state?

I ask because I would assume that if Stash is holding a local copy of the Crowd directory I would think it should be able to work even if Crowd was down.  Though we didn't experience this ourselves. We had a Crowd outage after an upgrade was done from 2.6.5 -> 2.7.1 which resulted in a cascade of all our other systems using Crowd to become completely unresponsive.

Caspar Krieger · Accepted Answer

The cache maintained by other Atlassian products is in place for performance only; when Crowd goes down, I would expect the other applications to at least lose functionality, if not completely fail.

This is because there are some things which can't be done by the other Atlassian products when Crowd is offline (such as checking a user's password, because applications never get their user's passwords; this is a consequence of the fact that Crowd itself may not have the passwords for users in the case where it's connected to LDAP).