> -----Original Message----- > From: ceph-devel-ow...@vger.kernel.org [mailto:ceph-devel- > ow...@vger.kernel.org] On Behalf Of Somnath Roy > Sent: Tuesday, October 13, 2015 8:46 AM > > Thanks Haomai.. > Since Async messenger is always using a constant number of threads , there > could be a potential performance problem of scaling up the client > connections keeping the constant number of OSDs ? > May be it's a good tradeoff..
It's not that big issue when you look realistically at it. In fact, having more threads than around 2 * available_logical_cpus is going to drag performance down, so it's better to have thread wait than make it forcing context switches. The point of using more threads per process is to have it spend less time waiting for I/O and better utilize current multi-core CPUs. Having threads fighting for CPU and/or I/O time is worse than having them underutilized, which is particularly true with spinning drives (which aren't going anywhere any soon; not every customer is going to accept $1700 price tag per drive that has only 800GB of capacity) and slower CPUs (again, not every customer is going to accept $1200 price tag per CPU). With best regards / Pozdrawiam Piotr Dałek _______________________________________________ ceph-users mailing list ceph-users@lists.ceph.com http://lists.ceph.com/listinfo.cgi/ceph-users-ceph.com
