Description of problem: The lmtpd process appears to do group lookups using getgrent() instead of getgrnam() therefore bypassing using the local nscd cache, this causes a great deal of network traffic and queries to ldap or nis servers. On a busy mail server this causes mail to be slow and the load on the ldap server to rise. There is a patch around to use a group.cache file, but it is not implemented in our release. Version-Release number of selected component (if applicable): cyrus-imapd-2.2.12-3.RHEL4.1 How reproducible: Instantly noticable in our environment when using ldap. Steps to Reproduce: 1. Change auth mechanism to ldap client 2. restart cyrus-imapd 3. Watch network traffic and ldap queries to ldap server Actual results: Expected results: Additional info: I think the best work around would be to get cyrus to use nscd thereby reducing the number or queries to the ldap server. I tried using "ldap_sasl: 0" in /etc/imapd.conf, but this had little effect.
This request was evaluated by Red Hat Product Management for inclusion in a Red Hat Enterprise Linux maintenance release. Product Management has requested further review of this request by Red Hat Engineering, for potential inclusion in a Red Hat Enterprise Linux Update release for currently deployed products. This request is not yet committed for inclusion in an Update release.
(In reply to comment #1) > This bug is seriously effecting our internal infrastructure AFAIK... Adding to > the RHEL 4.5 list. Peter, what are the chances this can be addressed? Perhaps we can recruit some testing from IS. :) + qa_ack for rhel-4.5
Mark/Nate: Can you help QE in testing this?
After investigating the issue, the proper solution is not a private caching scheme for cyrus (proposed patch above), but using getgrouplist library call instead of pulling down complete list of all groups. I have verified that nscd cache is used for this call properly. Now just need to write the patch and verify that it works correctly :).
Created attachment 137671 [details] proposed patch
Asking for feedback from reporter. There are now cyrus-imapd rpm packages available (cyrus-imapd-2.2.12-7.RHEL4.*), so I would like to ask the reporter to provide the feedback if the network traffic and queuries to ldap or nis server improves with these new packages installed. Or pls provide more configuration details so I can verify your problem (and consequently it's solution :o)) Thanks
I tested the patch supplied by Tomas Janousek and this seems to have fixed group lookup issue in my test environment so many thanks.
An advisory has been issued which should help the problem described in this bug report. This report is therefore being closed with a resolution of ERRATA. For more information on the solution and/or where to find the updated files, please follow the link below. You may reopen this bug report if the solution does not work for you. http://rhn.redhat.com/errata/RHBA-2007-0258.html