OpenLDAP and file limits

[Bevan C. Bennett]

Ok, I am having one really big problem with using FC1 as a server in one 
particular circumstance. Every week or so, LDAP hits 'Too many open 
files' and stops functioning properly. Additionally, I've discovered 
that the various LDAP clients don't then fail over to my backup LDAP 
server like they're supposed to. They don't even fail all at once, but 
things just slowly stop working one by one until everything else grinds 
to a halt.

I've seen other people with similar problems, but no useful solutions 
being offered. My old Redhat7.1 server never had this problem running 
openldap 2.0.11.

Jan 11 04:38:09 urd slapd[1452]: warning: cannot open /etc/hosts.allow: 
Too many open files
Jan 11 04:38:47 urd last message repeated 18 times
Jan 11 04:39:52 urd last message repeated 7 times
Jan 11 04:42:55 urd last message repeated 24 times
Jan 11 04:45:36 urd last message repeated 2 times
Jan 11 04:50:37 urd last message repeated 8 times
Jan 11 05:12:17 urd last message repeated 3 times
Jan 11 05:13:58 urd last message repeated 7 times
Jan 11 05:33:57 urd last message repeated 2 times
Jan 11 05:35:38 urd last message repeated 4 times
Jan 11 05:40:46 urd last message repeated 14 times
[...]
Jan 16 09:43:00 urd slapd[3021]: warning: cannot open /etc/hosts.allow: 
Too many open files
Jan 16 09:43:38 urd last message repeated 9 times
Jan 16 09:44:45 urd last message repeated 11 times
Jan 16 09:45:01 urd last message repeated 14 times

I've tried adding the following to /etc/security/limits.conf, but it 
hasn't helped:
ldap             hard    nofile          65535

It looks like I'd need to have ldap run 'ulimit -n 65535' before 
starting slapd from either within the daemon function of 
/etc/init.d/functions or some wrapper script, but I'm a little baffled 
as to why this behavior never showed up on my older system which has 
AFAIK the same per-process user limits.

Does anyone have any insight or helpful suggestions (other than putting 
together a PO for a few RHEL licenses)?