From mboxrd@z Thu Jan 1 00:00:00 1970 From: Gregory Farnum Subject: Re: [ceph-users] More writes on filestore than on journal ? Date: Mon, 23 Mar 2015 07:29:05 -0700 Message-ID: References: <1427116891.16770.25.camel@daevel.fr> Mime-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: QUOTED-PRINTABLE Return-path: Received: from mail-ie0-f172.google.com ([209.85.223.172]:34025 "EHLO mail-ie0-f172.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752120AbbCWO3H convert rfc822-to-8bit (ORCPT ); Mon, 23 Mar 2015 10:29:07 -0400 Received: by iedfl3 with SMTP id fl3so42446130ied.1 for ; Mon, 23 Mar 2015 07:29:06 -0700 (PDT) Received: from mail-ie0-f174.google.com (mail-ie0-f174.google.com. [209.85.223.174]) by mx.google.com with ESMTPSA id j87sm699469iod.21.2015.03.23.07.29.05 for (version=TLSv1.2 cipher=ECDHE-RSA-AES128-GCM-SHA256 bits=128/128); Mon, 23 Mar 2015 07:29:06 -0700 (PDT) Received: by ieclw3 with SMTP id lw3so36802960iec.2 for ; Mon, 23 Mar 2015 07:29:05 -0700 (PDT) In-Reply-To: <1427116891.16770.25.camel@daevel.fr> Sender: ceph-devel-owner@vger.kernel.org List-ID: To: Olivier Bonvalet Cc: ceph-users , "ceph-devel@vger.kernel.org" On Mon, Mar 23, 2015 at 6:21 AM, Olivier Bonvalet = wrote: > Hi, > > I'm still trying to find why there is much more write operations on > filestore since Emperor/Firefly than from Dumpling. Do you have any history around this? It doesn't sound familiar, although I bet it's because of the WBThrottle and flushing changes. > > So, I add monitoring of all perf counters values from OSD. > > From what I see : =C2=ABfilestore.ops=C2=BB reports an average of 78 = operations > per seconds. But, block device monitoring reports an average of 113 > operations per seconds (+45%). > please thoses 2 graphs : > - https://daevel.fr/img/firefly/osd-70.filestore-ops.png > - https://daevel.fr/img/firefly/osd-70.sda-ops.png That's unfortunate but perhaps not surprising =E2=80=94 any filestore o= p can change a backing file (which requires hitting both the file and the inode: potentially two disk seeks), as well as adding entries to the leveldb instance. -Greg > > Do you see what can explain this difference ? (this OSD use XFS) > > Thanks, > Olivier > > _______________________________________________ > ceph-users mailing list > ceph-users@lists.ceph.com > http://lists.ceph.com/listinfo.cgi/ceph-users-ceph.com -- To unsubscribe from this list: send the line "unsubscribe ceph-devel" i= n the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html