From: Andreas Dilger <adilger@sun.com>
To: lustre-devel@lists.lustre.org
Subject: [Lustre-devel] COS performance issues
Date: Sat, 11 Oct 2008 10:00:10 -0600 [thread overview]
Message-ID: <20081011160010.GR2009@webber.adilger.int> (raw)
In-Reply-To: <200810081544.08292.alexander.zarochentsev@sun.com>
On Oct 08, 2008 15:44 +0400, Alexander Zarochentsev wrote:
> I think the problem is that COS defers processing of replies to
> transaction commit time. When commit happens, MDS has to process
> thousands of replies (about 14k replies per commit in the test 3.a)
> in short period of time. I guess the mdt service threads all woken
> up and spin trying to get the service svr_lock. Processing of new
> requests may also suffer of this.
Can you please explain what replies are being blocked? It can't be the
create replies or the clients would be blocked waiting after starting a
single create each.
I think the thread and lock contention is only part of the issue - if all
of these replies are blocked until transaction commit this wastes all of
the bandwidth on the network while the replies are being held.
Cheers, Andreas
--
Andreas Dilger
Sr. Staff Engineer, Lustre Group
Sun Microsystems of Canada, Inc.
next prev parent reply other threads:[~2008-10-11 16:00 UTC|newest]
Thread overview: 13+ messages / expand[flat|nested] mbox.gz Atom feed top
2008-10-08 11:44 [Lustre-devel] COS performance issues Alexander Zarochentsev
2008-10-08 11:48 ` Alex Zhuravlev
2008-10-12 18:41 ` Alexander Zarochentsev
2008-10-12 19:12 ` Alex Zhuravlev
2008-10-13 14:36 ` Alexander Zarochentsev
2008-10-13 15:04 ` Alex Zhuravlev
2008-10-17 8:07 ` Alexander Zarochentsev
2008-10-17 20:55 ` Robert Read
2008-10-18 10:34 ` Alexander Zarochentsev
2008-10-11 16:00 ` Andreas Dilger [this message]
2008-10-11 20:18 ` Eric Barton
2008-10-12 15:51 ` Alexander Zarochentsev
-- strict thread matches above, loose matches on Subject: below --
2008-10-08 6:40 Alexander Zarochentsev
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