From: Stefan Priebe <s.priebe@profihost.ag>
To: Sage Weil <sage@inktank.com>
Cc: "ceph-devel@vger.kernel.org" <ceph-devel@vger.kernel.org>
Subject: Re: ceph-osd cpu usage
Date: Thu, 15 Nov 2012 21:26:06 +0100 [thread overview]
Message-ID: <50A54FDE.9070403@profihost.ag> (raw)
In-Reply-To: <alpine.DEB.2.00.1211150710550.4011@cobra.newdream.net>
Am 15.11.2012 16:14, schrieb Sage Weil:
> On Thu, 15 Nov 2012, Stefan Priebe - Profihost AG wrote:
> Hmm, most significant time seems to be in the allocator and doing
> fsetxattr(2) (10%!). Also some path traversal stuff.
Yes fsetxattr seems to be CPU hungry.
> Can you try the wip-fd-simple-cache branch, which tries to spend less time
> closing and reopening files? I'm curious how much of a different it will
> make for you for both IOPS and CPU utilization.
It seems to give me around 1000 iops across 3 VMs.
> It is also possible to use leveldb for most attrs. If you set
> 'filestore xattr use omap = true' it should put most attrs in leveldb.
Tried this but this raises CPU by 20%.
Any other ideas how to reduce ceph-osd while doing randwrite?
Randread gives me with 3 VMs: 60.000 iops
Randwrite gives me with 3 VMs: 25.000 iops
Stefan
next prev parent reply other threads:[~2012-11-15 20:26 UTC|newest]
Thread overview: 12+ messages / expand[flat|nested] mbox.gz Atom feed top
2012-11-15 10:56 ceph-osd cpu usage Stefan Priebe - Profihost AG
2012-11-15 11:18 ` Alexandre DERUMIER
2012-11-15 12:19 ` Stefan Priebe - Profihost AG
2012-11-15 15:12 ` Mark Nelson
2012-11-15 16:09 ` Stefan Priebe
2012-11-15 16:52 ` Sage Weil
2012-11-15 19:44 ` Stefan Priebe
2012-11-15 15:14 ` Sage Weil
2012-11-15 15:30 ` Stefan Priebe - Profihost AG
2012-11-15 20:26 ` Stefan Priebe [this message]
2012-11-16 8:41 ` Alexandre DERUMIER
2012-11-16 9:11 ` Stefan Priebe - Profihost AG
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