slapd: warning: cannot open /etc/hosts.allow: Too many open files

[Sérgio "M. Basto" <sbasto@fe.up.pt>]

Hi, 

We have one implementation of openldap for 12000 accounts with 1 openldap master and 3 slaves
over ssl with versions 2.2.13 and 2.2.14 
This solution is working for 4 months, now, in this days, with a very high network traffic, begins appears this little problem,
I have to stop ldap slave and restart it again.

I begging have this error on one slave on one Red had Enterprise Server AS 3 Update 3 

Dec  6 15:26:30 maila slapd[19722]: warning: cannot open /etc/hosts.allow: Too many open files
Dec  6 15:26:30 maila slapd[19722]: error: bad option name: "ould"

I had made one src.rpm for this OS to run openldap 2.2.14 , others slaves and Master are in Slackware and are 2.2.13 , 
The strange is: 
on slack with 2.2.13, I have more then 10 slapd processes 
on Red Hat with 2.2.14, I just have only one slapd process.
This is normal ?
what I can do for Redhat open more slapd processes 

I would like know what happens and What I can do to prevent this problem. When this problem occurs the users doesn't get in.

thanks,

--
Sérgio M. B.