On Sat, Apr 2, 2011 at 10:18 AM, Dimitri Maziuk <[email protected]> wrote: > On 4/2/2011 12:40 AM, Vadym Chepkov wrote: > >> Ok, lets see how this might work. >> You would need a separate monitor for the cluster and since this >> monitor also can potentially crash, you would need another monitor to >> observer the first one, then we would want the first one to monitor >> second one, so we would need a cluster of monitors. > > That is precisely why I'm happy with heartbeat 2.1.4 in R1 setup: > simple, stupid, and I know exactly what failures it will handle and what > problems it monitors for (because I wrote the mon scripts).
Old shoes always feet better. > >> Wait, don't we have already cluster in place? It seems logical to have >> monitor to be part of the cluster. I was expecting "monitor" operation >> to handle that, but it seems for DRBD this is not the case. > > This is also not the case with e.g. apache once you think about it: the > agent checks it wget of /server-status on locahost returns success. > There's 3 things wrong with that, the one relevant here is that kernel > should be smart enough to route the packets over lo even if you're > wget'ting from cluster ip. As a result you cannot check if a daemon is > answering on cluster ip if you run the check on active node. > > So you have to have an external monitor. Don't you have one to monitor > your switches and upsen and not-clustered kit anyway? True for basic setup. Not true if you carefully study Apache RA. > >> Maybe we >> should have another primitive running? drbd_status or something? >> When drbd subsystem is in degraded state, have drbd_status in "stopped" >> state? > > Drbd has its own logic for figuring out its state. Controlled via > drbd.conf -- adjust drbd.conf so the secondary does not start in > degraded state. And shuts down when split brain is detected. > > Dima > > > Dima > _______________________________________________ > Linux-HA mailing list > [email protected] > http://lists.linux-ha.org/mailman/listinfo/linux-ha > See also: http://linux-ha.org/ReportingProblems > -- Serge Dubrouski. _______________________________________________ Linux-HA mailing list [email protected] http://lists.linux-ha.org/mailman/listinfo/linux-ha See also: http://linux-ha.org/ReportingProblems
