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Re: openldap core dumping under load

I should note that openldap 2.1.16/sendmail-8.12.8 is performing very well in my environment on slackware linux. I have a 1.2GHZ dell server with a raid5 array (I know, not the best setup for mail) but was still able to turn about 2100 messages a minute for 8 straight hours without fail. I'm using the 2.4.20 kernel with the ext3 patches and also the new 2.0.3 megaraid driver.

I don't use the full-on sendmail-ldap routing table, but I have a couple of rules that lookup data in ldap and my virtusertable is also mapped to ldap.

Howard, any idea when the fixes in ITS# 2404 will make it to a release? I really try to avoid CVS releases in production.



Igor Brezac wrote:
I am not sure if this is related, but I noticed that sendmail using ldapi
fails to connect to the ldap server at random times under moderate to
heavy loads.  I changed to ldap://localhost/ and problem when away.  This
is not a very busy sendmail installation.


On Wed, 26 Mar 2003, Howard Chu wrote:

I believe part of the response problem may be due to how sendmail interacts
with LDAP, and part due to how slapd processes its input. Sendmail tends to
spew a ton of queries out in rapid succession, and slapd tends to try to read
all of its input before it processes any of it. There are two macros in
slapd/connection.c that affect slapd's behavior: CONNECTION_INPUT_LOOP and
DATA_READY_LOOP. If you comment out both of them, then slapd will read only
one message at a time. Try that, it may even out the response time.

Of course, pummeling a 350MHz PII with a 2.4GHz P4 may be part of your
problem too...

 -- Howard Chu
 Chief Architect, Symas Corp.       Director, Highland Sun
 http://www.symas.com               http://highlandsun.com/hyc
 Symas: Premier OpenSource Development and Support

-----Original Message-----
From: Gordon Shumway [mailto:gshumway@cityextreme.com]

Thanks Howard.

That certainly stopped the core dump.

The only issue now seems to be CPU. During these times of
unusually high
load, slapd seems to use enough of the CPU to cause responses
to be slow.
Slow enough for IMAP ldap auths to timeout. Everything comes
good once the
mail flow slows.

Maybe I just need a faster box.