Ever since implementing delta syncrepl replication on OpenLDAP version 2.3.20, I've had very sporadic (two to be precise) cases of slapd freezing up and stopping. Upon attempting to restart slapd, the accesslog database cannot be recovered automatically which effectively means that the LDAP server doesn't start up. Only after removing all files pertaining to the accesslog backend does slapd start. Hoping to solve the problem with a newer software version, I upgraded to the latest release version of OpenLDAP: 2.3.28. Initially all was fine and dandy: I configured and installed the software, started up the slapd server and lay back to relax. Unfortunately slapd crashed last night without any apparent reason (no log entries), so I'm a little worried. Good that Nagios is holding watch for me. Update: I have downgraded to 2.3.27.