> > On Thu, Feb 23, 2017 at 3:15 PM, Timo Sirainen <t...@iki.fi> wrote: > >> On 24 Feb 2017, at 0.08, Mark Moseley <moseleym...@gmail.com> wrote: >> > >> > As someone who is about to begin the process of moving from maildir to >> > mdbox on NFS (and therefore just about to start the 'director-ization' >> of >> > everything) for ~6.5m mailboxes, I'm curious if anyone can share any >> > experiences with it. The list is surprisingly quiet about this subject, >> and >> > articles on google are mainly just about setting director up. I've yet >> to >> > stumble across an article about someone's experiences with it. >> > >> > * How big of a director cluster do you use? I'm going to have millions >> of >> > mailboxes behind 10 directors. >> >> I wouldn't use more than 10. >> >> > Cool > > > >> > I'm guessing that's plenty. It's actually split over two datacenters. >> >> Two datacenters in the same director ring? This is dangerous. if there's >> a network connectivity problem between them, they split into two separate >> rings and start redirecting users to different backends. >> > > I was unclear. The two director rings are unrelated and won't ever need to > talk to each other. I only mentioned the two rings to point out that all > 6.5m mailboxes weren't behind one ring, but rather split between two > > > >> >> > * Do you have consistent hashing turned on? I can't think of any reason >> not >> > to have it turned on, but who knows >> >> Definitely turn it on. The setting only exists because of backwards >> compatibility and will be removed at some point. >> >> > Out of curiosity (and possibly extremely naive), unless you've moved a > mailbox via 'doveadm director', if someone is pointed to a box via > consistent hashing, why would the directors need to share that mailbox > mapping? Again, assuming they're not moved (I'm also assuming that the > mailbox would always, by default, hash to the same value in the consistent > hash), isn't their hashing all that's needed to get to the right backend? > I.e. "I know what the mailbox hashes to, and I know what backend that hash > points at, so I'm done", in which case, no need to communicate to the other > directors. I could see that if you moved someone, it *would* need to > communicate that mapping. Then the only maps traded by directors would be > the consistent hash boundaries *plus* any "moved" mailboxes. Again, just > curious. > > Timo, Incidentally, on that error I posted:
Feb 12 06:25:03 director: Warning: director(10.1.20.3:9090/left): Host 10.1.17.3 is being updated before previous update had finished (up -> down) - setting to state=down vhosts=0 Feb 12 06:25:03 director: Warning: director(10.1.20.3:9090/left): Host 10.1.17.3 is being updated before previous update had finished (down -> up) - setting to state=up vhosts=0 any idea what would cause that? Is my guess that multiple directors tried to update the status simultaneously correct?
