I had similar issue a while back with like the 2.2 or 2.3 series, and part of the database was corrupt. The database couldn't respond to xyz search and I assume would leave the sockets hanging thus use them all up. I ended up rebuilding the database.
Quoting Dieter Kluenter dieter@dkluenter.de:
Klemens Kittan kittan@cs.uni-potsdam.de writes:
Hello,
the problem is, that many clients generate more than 1024 concurrent sockets to the LDAP service which block the remaining incoming sockets.
I already do all the possible changes to the server (ulimit, sysctl, etc) without a solution. All the incoming connections stop at the 1024 concurrent sockets. The only solution is restarting slapd.
The version of openldap is 2.4.11.
In /var/log/syslog I found the following entry:
Mar 1 14:45:15 ldap1 slapd[25320]: warning: /etc/hosts.allow, line 19: cannot open /etc/hosts.allow: Too many open files
Do you really need tcp wrapper support?
-Dieter
-- Dieter Klünter | Systemberatung http://dkluenter.de GPG Key ID:8EF7B6C6 53°37'09,95"N 10°08'02,42"E