Mike, yeah, I wouldn't switch to rdma until it is fully supported in a stable 
release ))) 

Andrei 

----- Original Message -----

> From: "Andrei Mikhailovsky" <[email protected]>
> To: "Somnath Roy" <[email protected]>
> Cc: [email protected], "ceph-devel"
> <[email protected]>
> Sent: Wednesday, 8 April, 2015 7:16:40 PM
> Subject: Re: [ceph-users] Preliminary RDMA vs TCP numbers

> Somnath,

> Sounds very promising! I can't wait to try it on my cluster as I am
> currently using IPOIB instread of the native rdma.

> Cheers

> Andrei

> ----- Original Message -----

> > From: "Somnath Roy" <[email protected]>
> 
> > To: "Andrei Mikhailovsky" <[email protected]>, "Andrey Korolyov"
> > <[email protected]>
> 
> > Cc: [email protected], "ceph-devel"
> > <[email protected]>
> 
> > Sent: Wednesday, 8 April, 2015 5:23:23 PM
> 
> > Subject: RE: [ceph-users] Preliminary RDMA vs TCP numbers
> 

> > Andrei,
> 
> > Yes, I see it has lot of potential and I believe fixing the
> > performance bottlenecks inside XIO messenger it should go further.
> 
> > We are working on it and will keep community posted..
> 

> > Thanks & Regards
> 
> > Somnath
> 

> > From: Andrei Mikhailovsky [mailto:[email protected]]
> 
> > Sent: Wednesday, April 08, 2015 2:22 AM
> 
> > To: Andrey Korolyov
> 
> > Cc: [email protected]; ceph-devel; Somnath Roy
> 
> > Subject: Re: [ceph-users] Preliminary RDMA vs TCP numbers
> 

> > Hi,
> 

> > Am I the only person noticing disappointing results from the
> > preliminary RDMA testing, or am I reading the numbers wrong?
> 

> > Yes, it's true that on a very small cluster you do see a great
> > improvement in rdma, but in real life rdma is used in large
> > infrastructure projects, not on a few servers with a handful of
> > osds. In fact, from what i've seen from the slides, the rdma
> > implementation scales horribly to the point that it becomes slower
> > the more osds you through at it.
> 

> > From my limited knowledge, i have expected a much higher
> > performance
> > gains with rdma, taking into account that you should have much
> > lower
> > latency and overhead and lower cpu utilisation when using this
> > transport in comparison with tcp.
> 

> > Are we likely to see a great deal of improvement with ceph and rdma
> > in a near future? Is there a roadmap for having a stable and
> > reliable rdma protocol support?
> 

> > Thanks
> 

> > Andrei
> 
> > ----- Original Message -----
> 

> > > From: "Andrey Korolyov" < [email protected] >
> > 
> 
> > > To: "Somnath Roy" < [email protected] >
> > 
> 
> > > Cc: [email protected] , "ceph-devel" <
> > > [email protected] >
> > 
> 
> > > Sent: Wednesday, 8 April, 2015 9:28:12 AM
> > 
> 
> > > Subject: Re: [ceph-users] Preliminary RDMA vs TCP numbers
> > 
> 

> > > On Wed, Apr 8, 2015 at 11:17 AM, Somnath Roy <
> > > [email protected] > wrote:
> > 
> 
> > > >
> > 
> 
> > > > Hi,
> > 
> 
> > > > Please find the preliminary performance numbers of TCP Vs RDMA
> > > > (XIO) implementation (on top of SSDs) in the following link.
> > 
> 
> > > >
> > 
> 
> > > > http://www.slideshare.net/somnathroy7568/ceph-on-rdma
> > 
> 
> > > >
> > 
> 
> > > > The attachment didn't go through it seems, so, I had to use
> > > > slideshare.
> > 
> 
> > > >
> > 
> 
> > > > Mark,
> > 
> 
> > > > If we have time, I can present it in tomorrow's performance
> > > > meeting.
> > 
> 
> > > >
> > 
> 
> > > > Thanks & Regards
> > 
> 
> > > > Somnath
> > 
> 
> > > >
> > 
> 

> > > Those numbers are really impressive (for small numbers at least)!
> > > What
> > 
> 
> > > are TCP settings you using?For example, difference can be lowered
> > > on
> > 
> 
> > > scale due to less intensive per-connection acceleration on CUBIC
> > > on
> > > a
> > 
> 
> > > larger number of nodes, though I do not believe that it was a
> > > main
> > 
> 
> > > reason for an observed TCP catchup on a relatively flat workload
> > > such
> > 
> 
> > > as fio generates.
> > 
> 
> > > _______________________________________________
> > 
> 
> > > ceph-users mailing list
> > 
> 
> > > [email protected]
> > 
> 
> > > http://lists.ceph.com/listinfo.cgi/ceph-users-ceph.com
> > 
> 
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