Openldap 2.1.25 crashing

["James Courtney" <Jcourtney@inphonic.com>]

Periodically and seemingly under load our OpenLDAP server just stops (no pid when we go into the server).  We're using 2.1.25 backed by BDB 4.2.52 and OpenSSL 0.9.7d on RedHat Enterprise 3 ES Linux.

I don't see a core file anywhere so it seems to just die.  Has anyone else seen such behavior?

We are suspicious of our LDAP load of late as several times a day we're seeing enough load generated by our mail server that searches are timing out (for the client doing the searching).  Our directory is only 20k entries and I set the "cachesize" in slapd.conf to 1 million since we've got plenty of memory.  All of our search attributes seem correctly indexed too. 

Also, does anyone have a good resource for slapd performance tuning with the BDB backend?  I've read that I can set some backend caching parameters in BDB itself but I was hoping there was a performance tuning guide that would cover all of that sort of thing in context for me.

Many thanks!

James "Jamey" Courtney
InPhonic, Inc.