[Date Prev][Date Next] [Chronological] [Thread] [Top]

Re: RE24 (2.4.15) slapd consuming large amounts of CPU

John Morrissey wrote:
I upgraded one of our consumers to 2.4.15 recently, from RE24 as of
20090113. Its configuration stayed the same, save for bumping the BDB cache
size from 256MB to 2GB.

After a few hours of uptime, slapd suddenly begins consuming enormous
amounts of CPU (a three- to four-fold increase over less than a few minutes,
and is sustained until slapd is restarted).

A backtrace (below) shows many threads waiting on a mutex in bdb_cache_*().

This is with BDB 4.7 (with all patches applied) on Debian lenny.
'db_stat -c' output is below (and looks sane), in case that's useful.
Thinking thread contention, I bumped the worker thread count (slapd.conf
threads directive) down from 32 to 8, which has made no difference.

From the trace it looks similar to ITS#5860. The patches for this are in HEAD, not yet released.

  -- Howard Chu
  CTO, Symas Corp.           http://www.symas.com
  Director, Highland Sun     http://highlandsun.com/hyc/
  Chief Architect, OpenLDAP  http://www.openldap.org/project/