Re: subject=(ITS#2610)

[jongchoi@OpenLDAP.org]

It would help to look at the problem if you post "db_stat -c" result in the
list.
Also wondering whether the recent congestion control patch can solve this
problem,
but I suspect it because "Number of deadlocks" is zero in this case.
- Jong

----------------
Jong Hyuk Choi
IBM Thomas J. Watson Research Center - Enterprise Linux Group
P.O. Box 218, Yorktown Heights, NY 10598
email: jongchoi@us.ibm.com
(phone) 914-945-3979 (fax) 914-945-4425 TL: 862-3979
----- Original Message -----

From: <edg72@home.nl>
To: <openldap-its@OpenLDAP.org>
Sent: Thursday, June 26, 2003 5:17 PM
Subject: subject=(ITS#2610)


> Hi,
>
> I've done some futher investigation on this ITS and I've found out that it
is
> BerkeleyDB that is calling ldap_pvt_thread_yield() all the time (callback
> registered in /servers/slapd/back-bdb/init.c). This is the cause of the
high
> CPU usage and the large amount of context switches (over 100K/sec!) I've
> seen. I suspect there is some bdb locking problem going on. When I run
> db_stat -c while performing the modify benchmark I see that "Total number
of
> locks not immediately available due to conflicts" is steadily increasing,
I
> am not sure if that is a serious issue. The "Number of deadlocks" is zero
and
> there are no signs of BDB running out of locks/lockers/lock objects.
> I've also added some extra debug statements in
/servers/slapd/back-bdb/idl.c
> because from slapd's debug logging I saw that executing the function
> bdb_idl_delete_key() took al lot of time, sometimes more than 15 seconds!
> I'll try to continue with digging into this problem, but I am starting to
run
> out of ideas. Any ideas would be welcome!
>
> Regards,
>
> Erik
>
> PS I forgot to mention that I use BerkeleyDB 4.1.25p1 NC
>
>
>
>