Hello, Thanks both for your responses, defiantly looking at collectd + graphite, just wanted to see what overheads where like, far from in a situation that would choke the cluster but wanted to check first. Thanks, Ashley -----Original Message----- From: Christian Balzer [mailto:chibi@xxxxxxx] Sent: 24 October 2016 11:04 To: ceph-users@xxxxxxxxxxxxxx Cc: John Spray <jspray@xxxxxxxxxx>; Ashley Merrick <ashley@xxxxxxxxxxxxxx> Subject: Re: Monitoring Overhead Hello, On Mon, 24 Oct 2016 10:46:31 +0100 John Spray wrote: > On Mon, Oct 24, 2016 at 4:21 AM, Ashley Merrick <ashley@xxxxxxxxxxxxxx> wrote: > > Hello, > > > > > > > > This may come across as a simple question but just wanted to check. > > > > > > > > I am looking at importing live data from my cluster via ceph -s > > e.t.c into a graphical graph interface so I can monitor performance > > / iops / e.t.c overtime. > > > > > > > > I am looking to pull this data from one or more monitor nodes, when > > the data is retrieved for the ceph -s output is this information > > that the monitor already has locally or is there an overhead that is > > applied to the whole cluster to retrieve this data every time the command is executed? > > It's all from the local state on the mons, the OSDs aren't involved at > all in responding to the status command. > That said, as mentioned before on this ML, the output of "ceph -s" is a sample from a window and only approaching something reality if sampled and divided of a long period. If you need something that involves "what happened on OSD x at time y", collectd and graphite (or deviations of if) are your friends, but they do cost you a CPU cycle or two. OTOH, if your OSDs or MONs were to choke from that kind of monitoring, you're walking on very thin ice already. Christian > Cheers, > John > > > > > > > > > Reason I ask is I want to make sure I am not applying unnecessary > > overhead and load onto all OSD node’s to retrieve this data at a > > near live view, I fully understand it will apply a small amount of > > load / CPU on the local MON to process the command, I am more interesting in overall cluster. > > > > > > > > Thanks, > > > > Ashley > > > > > > _______________________________________________ > > ceph-users mailing list > > ceph-users@xxxxxxxxxxxxxx > > http://lists.ceph.com/listinfo.cgi/ceph-users-ceph.com > > > _______________________________________________ > ceph-users mailing list > ceph-users@xxxxxxxxxxxxxx > http://lists.ceph.com/listinfo.cgi/ceph-users-ceph.com -- Christian Balzer Network/Systems Engineer chibi@xxxxxxx Global OnLine Japan/Rakuten Communications http://www.gol.com/ _______________________________________________ ceph-users mailing list ceph-users@xxxxxxxxxxxxxx http://lists.ceph.com/listinfo.cgi/ceph-users-ceph.com
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