> Op 6 september 2016 om 14:43 schreef John Spray <jspray@xxxxxxxxxx>: > > > On Tue, Sep 6, 2016 at 1:12 PM, Wido den Hollander <wido@xxxxxxxx> wrote: > > Hi, > > > > Recent threads on on the ML revealed that the Ceph MDS can benefit from using a fast single threaded CPU. > > > > Some tasks inside the MDS are still single-threaded operations, so the faster the code executes the better. > > > > Keeping that in mind I started to look at some benchmarks: http://cpubenchmark.net/singleThread.html > > > > The fastest server CPU there is the "Intel Xeon E3-1281 v3 @ 3.70GHz". > > > > This is a 4-core CPU, however, it can only address 32GB of memory. Which is not much in most situations. > > > > The "Intel Xeon E5-1650 v4 @ 3.60GHz" however would also be a good candidate. It can address up to 1.5TB of DDR4 memory. The 6-cores should also be sufficient. > > > > Is this a good assumption to make? > > > > - E5-1650 v4 @ 3.60GHz > > - 256GB of memory > > - Disable all CPU powersaving (c-state to 0) > > > > Does this make any sense for a Ceph MDS? > > Recent testing saw creates peak at around 5000 ops/s on an E5-2650 > (Ben England) and a similar number on E5-2680 (eBay). I don't think > anyone has tried with a higher clocked single socket CPU -- it's > reasonable to expect some improvement, although it might not be > dramatic. I would love to see the results. > I have the E5-1650s running at a customer as SSD nodes, but this cluster is still Hammer without CephFS. Probably won't be able to get these boxes free for testing since it's all in production already. But up until how much cores do you think the MDS will scale? It's a 6-core CPU in this case. Would a 8-core provide much more performance looking at the MDS? If I run these tests, any suite you would run against it so I get the same benchmark ran on those systems? Wido > John > > > > > Wido > > _______________________________________________ > > 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
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