On Fri, Dec 21, 2012 at 2:07 AM, Amon Ott <ao@xxxxxxxxxxxx> wrote: > Am 20.12.2012 15:31, schrieb Mark Nelson: >> On 12/20/2012 01:08 AM, Roman Hlynovskiy wrote: >>> Hello Mark, >>> >>> for multi-mds solutions do you refer to multi-active arch or 1 active >>> and many standby arch? >> >> That's a good question! I know we don't really recommend multi-active >> right now for production use. Not sure what our current recommendations >> are for multi-standby. As far as I know it's considered to be more >> stable. I'm sure Greg or Sage can chime in with a more accurate >> assessment. > > We have been testing a lot with multi-standby, because a single MDS does > not make a lot of sense in a cluster. Maybe the clue is to have only one > standby, making SPOF a DPOF? The number of standbys should not have any impact on stability — they are read-only until the active MDS gets declared down, at which point one of them becomes active. I suppose having a standby could reduce stability if your active MDS is overloaded enough to miss check-ins without actually going down — without a standby it would eventually recover, but with a standby a transition happens. That's the only difference, though. -Greg -- To unsubscribe from this list: send the line "unsubscribe ceph-devel" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
