RHEL4 related OpenLDAP master/slave question

[Jukka Hienola <jukka.hienola@helsinki.fi>]

Dear all,

I have set up and run successfully OpenLDAP 2.2.13-4 server as a master 
and slave server with replication so far, until something happened about 
a week ago. My slave ldap server stopped completely to answer any read 
requests to it's ldap directory. E.g. any ldapsearch command just hangs 
returning noting more than some info about the server. E.g. simple 
command like 'ldapsearch -x -v -h localhost uid=someuser' just print out

  ldap_initialize( ldap://localhost )
  filter: uid=someuser
  requesting: ALL
  # extended LDIF
  #
  # LDAPv3
  # base <> with scope sub
  # filter: uid=someuser
  # requesting: ALL
  #

and hangs, so I have to CTRL^C to kill it. Also my slave server doesn't 
return anymore reference to master server with any write or modification 
requests. I have no idea what could have changed. My firewall settings 
are ok (unchanged), certificate files are ok (not expired), and also 
both slapd.conf files (on master and slave) are unchanged. Replication 
from master to slave works. DNS should be ok.

All the time I have had some problems with nscd and ldap 
interoperability. Somethimes I can't anymore get any user data with id 
command on my slave server without restarting ldap service. Also slurpd
hangs on master server when starting it with '/sbin/service ldap start' 
command, but is still running.

I have completely run out of ideas where the problem would lie. I would 
appreciate any kind of help!

Some version info:
kernel-2.6.9-22.0.1
openldap-servers-2.2.13-4
openldap-devel-2.2.13-4
openldap-2.2.13-4
nss_ldap-226-10
openldap-clients-2.2.13-4
nscd-2.3.4-2.13

Jukka Hienola
--
IT Services Administrator, Department of Physical Sciences,
University of Helsinki, firstname lastname at helsinki fi,
tel. +358 (0)9 191 50713, fax. +358 (0)9 191 50610