Hi Eugen, On 4/6/22 09:47, Eugen Block wrote: > I don't mean to hijack this thread, I'm just curious about the > multiple mirror daemons statement. Last year you mentioned that > multiple daemons only make sense if you have different pools to mirror > [1], at leat that's how I read it, you wrote: > >> [...] but actually you can have multiple rbd-mirror daemons per >> cluster. It's the number of peers that are limited to one remote >> peer per pool. So technically if using different pools, you should >> be able to have three clusters connected as long as you have only >> one remote peer per pool. I never tested it though... >> [...] For further multi-peer support, I am currently working on >> adding support for it! > > What's the current status on this? In the docs I find only a general > statement that pre-Luminous you only could have one rbd mirror daemon > per cluster. Sorry if my last year message was confusing... I was talking about adding multiple clusters as peer, so essentially doing `rbd mirror pool peer add [...]` (or similar) on the same pool and cluster multiple times which is still not possible in any stable version now (still progressing on the matter in a PR upstream, I still have a few bugs but it mostly works). But indeed, yes you can launch multiple rbd-mirror daemons quite easily. If you launch multiple rbd-mirror daemons on the same cluster, they will elect a leader among themselves and then the leader will try to maintain a equal amount of image each deamon handle. And there is no special trick about distributing the work in multiple pools, each daemon should handle images on all the pools where rbd replication is enabled. You can see who is the leader etc with `rbd mirror pool status --verbose`, for instance on one of our cluster: ``` $ rbd mirror pool status --verbose barn-mirror [...] DAEMONS service 149710145: instance_id: 149710151 client_id: barn-rbd-mirror-b hostname: barn-rbd-mirror-b.cern.ch version: 15.2.xx leader: false health: OK service 149710160: instance_id: 149710166 client_id: barn-rbd-mirror-c hostname: barn-rbd-mirror-c.cern.ch version: 15.2.xx leader: false health: OK service 149781483: instance_id: 149710136 client_id: barn-rbd-mirror-a hostname: barn-rbd-mirror-a.cern.ch version: 15.2.xx leader: true health: OK [...] ``` Cheers, -- Arthur Outhenin-Chalandre _______________________________________________ ceph-users mailing list -- ceph-users@xxxxxxx To unsubscribe send an email to ceph-users-leave@xxxxxxx
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