Hope this will be helpful..
Total connections per osd = (Target PGs per osd) * (# of pool replicas) * 3 + (2 #clients) + (min_hb_peer) # of pool replicas = configurable, default is 3 3 = is number of data communication messengers (cluster, hb_backend, hb_frontend) min_hb_peer = default is 20 I guess.. Total number connections per node: total connections per osd * number of osds per node Thanks & Regards Somnath From: ceph-users [mailto:ceph-users-boun...@lists.ceph.com] On Behalf Of Rick Balsano Sent: Wednesday, November 04, 2015 12:28 PM To: ceph-users@lists.ceph.com Subject: Re: [ceph-users] Understanding the number of TCP connections between clients and OSDs Just following up since this thread went silent after a few comments showing similar concerns, but no explanation of the behavior. Can anyone point to some code or documentation which explains how to estimate the expected number of TCP connections a client would open based on read/write volume, # of volumes, # of OSDs in the pool, etc? On Tue, Oct 27, 2015 at 5:05 AM, Dan van der Ster <d...@vanderster.com<mailto:d...@vanderster.com>> wrote: On Mon, Oct 26, 2015 at 10:48 PM, Jan Schermer <j...@schermer.cz<mailto:j...@schermer.cz>> wrote: > If we're talking about RBD clients (qemu) then the number also grows with > number of volumes attached to the client. I never thought about that but it might explain a problem we have where multiple attached volumes crashes an HV. I had assumed that multiple volumes would reuse the same rados client instance, and thus reuse the same connections to the OSDs. -- dan -- Rick Balsano Senior Software Engineer Opower<http://www.opower.com> O +1 571 384 1210<tel:%2B1%20571%20384%201210> We're Hiring! See jobs here<http://www.opower.com/careers>.
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