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Re: OpenLDAP (using BDB) stalls adding 65,536th entry

Mark Cooper wrote:

I've been doing some testing using OpenLDAP with BDB on a couple of different
platforms.  I noticed a similar situation.  When I sit in a loop doing adds,
at the 65,536th added entry the process stalls for a short period of time.
  After a minute or two, the add succeeds.  My first thought is that this is a
BDB issue, so I posted this question to Oracle's BDB forum.  But I have yet to
receive any answer.
This is all known/expected behavior. One (or more) of your index slots hit its maxsize of 65535 elements and was collapsed into a range. This typically happens with the objectClass index first, if you're adding a bunch of objects all of the same classes.
Taking a minute or two is abnormal, but I suppose is possible if multiple indices hit the condition at the same time. 


This situation seems to happen when I have around 43 10MB log files.  During
the stall, I notice many log files are being written (another 25 or so), which
is a much quicker rate than was being written prior to the stall.

The stall only happens once. I added another 350,000 entries and no more
stalls.  I ran a few other tests.  Added 65,535 entries.  All is fine.  As
soon as the next entry is add, even if I recycle the server, I hit the
condition.  I even tried deleting 1,000 entries.  I would then need to add
1,0001 to get to 65,536 entries in the database and then hit the delay.


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