When I write LDIFs to one node like delete user or remove user from group, we see spikes in authentication latency metrics (what's normally .2 - .5 second response time goes up to 15-30 seconds) across all nodes in the cluster at the same time.
I ran mdb_copy -c to compact the LDAP databases. The size went from 2.9G to 140M and the latency problem during inserts went away. I've noticed the LDAP data.mdb is growing about 25M per day. What accounts for the growth of free pages?
Do you have a lot of large groups that you frequently update?
Yes we have several groups with ~40k users from which we frequently add/remove users based on upstream user provisioning workflows.