[keycloak-dev] client query caches getting complicated

[Bill Burke]

Currently, adding or deleting a client, or updating a realm causes 
invalidation/eviction of the realm and all clients in that realm. To 
make matters worse, the next time the realm is accessed, it queries and 
loads each client and its relationships.  Why do we do this?  When a 
realm invalidation happens, the cache has no idea if the realm is just 
being updated or removed entirely from the DB. With a realm removal, you 
also need to evict the cache of all clients within the realm.  So, a 
cached realm MUST have a list of all clients within it.  As a result, 
the more clients that get added, keycloak gets slower and slower.  
Eventually though the cache stabilizes after inserts/update/deletes 
subside and we get back to normal performance, but you can see a nasty 
blip for a little bit.

I think i have a couple of solutions for this:

* Create a separate client cache. Client keys would be 
"{realm.id}.{client.id}".  Iterate on all client keys, and evict those 
that start with the realm id.
* Or, do a DB query for all clients of the realm.

I'm giving this until end of day to see if I can get a good solution, 
otherwise i'm aborting.

-- 
Bill Burke
JBoss, a division of Red Hat
http://bill.burkecentral.com