Hi Anthony, My main question is the number of connections between OSDs. Of course, CEPH cluster will have other additional connections. For example, if I have three cluster servers with 3 replication, and there are 12 OSDs on them. Then I test with FIO that there are 8 images in a pool. And the pool pgs num is 32. What is the theoretical connection tree between OSDs @Sam Just For the example above, per OSD connection number: (num_pgs/num_osds * (pool_size - 1))= (32/12*(3-1))=5.3? Does this have nothing to do with the number of threads and images started by the test? Best regards. Congmin Yin -----Original Message----- From: Anthony D'Atri <anthony.datri@xxxxxxxxx> Sent: Saturday, August 29, 2020 4:24 AM To: Sam Just <sjust@xxxxxxxxxx> Cc: Yin, Congmin <congmin.yin@xxxxxxxxx>; dev@xxxxxxx Subject: Re: question: the number of connections in ceph Last time I read through the code, there were a limited number of “extra” peerings added to the acting set OSDs too. But it’s a bit unclear what a “connection” means. And if that includes clients. > On Aug 28, 2020, at 12:56 PM, Sam Just <sjust@xxxxxxxxxx> wrote: > > I you're asking about the osd<->osd connection count for a particular > osd, it'll be proportional (two hearbeat connections and a cluster > connection per pair I think) to the number of osds that osd shares a > pg with (num_pgs/num_osds * (pool_size - 1)). > -Sam > > On Thu, Aug 27, 2020 at 1:38 AM Yin, Congmin <congmin.yin@xxxxxxxxx> wrote: >> >> Hi , >> >> >> >> I want to know the number of connections in CEPH. I think the connection is mainly OSD connection. >> >> Is the following statement correct? >> >> Each OSD is connected with other OSDs, and there may be more than one connection between two OSDs. >> >> If there is only one connection per OSD, the number of the connection is N(N-1)/2,. If there are k connections per OSD, the number of the connection is kN(N-1)/2. >> >> >> >> Thanks for your help. >> >> >> >> Best regards. >> >> Congmin Yin >> >> >> >> >> >> _______________________________________________ >> Dev mailing list -- dev@xxxxxxx >> To unsubscribe send an email to dev-leave@xxxxxxx > _______________________________________________ > Dev mailing list -- dev@xxxxxxx > To unsubscribe send an email to dev-leave@xxxxxxx _______________________________________________ Dev mailing list -- dev@xxxxxxx To unsubscribe send an email to dev-leave@xxxxxxx