Hi Valentin, On 05/17/2017 10:19 AM, Valentin Höbel wrote: > Hi Lee, > > thanks for taking the time for a) testing this stuff and b) writing an > answer. I appreciate the efforts! >
You're welcome! Sorry I don't have a simple answer for you, and I'm certainly not telling you how to set things up - just trying to provide some info/suggestions. > >> This failure scenario would require a serious network issue if your >> database cluster was architected to be highly available (any client >> node can connect to any server node). That's not to say perhaps >> it could not be handled better. > > That is not the point. It doesn't matter how "bad", "good" or "unusual" the > Galera HA setup is. The point is that Icinga2 doesn't failover although it > can't access the database. The Galera setup in this case is very special (and > yes, I do have reasons to build it that way and no, sorry, since this is a > customer project I can't tell you why, sorry, really). > My point is that it is somewhat reasonable that Icinga does not handle this failure scenario since it can be avoided with an HA topology. Perhaps it could be handled better, of course (as I said above). I presume the design assumption was that if one node cannot connect to the DB, the other nodes probably cannot connect either (the serious network issue scenario), so just continue to queue queries up until service is restored. DB connectivity awareness could be built in to Icinga, for example by passing a token between the nodes with "I can (not) connect to the DB" and electing a DB writer node. Pacemaker could probably accomplish this, and there are other ways (e.g. Monit), but another thought is: - If the local Galera crashes, consider that node failed entirely and shutdown the local Icinga (potentially causing the DB writer to failover as well). You'll have to weigh the tradeoffs according to your own situation and requirements. Kind Regards, Lee Clemens _______________________________________________ icinga-users mailing list icinga-users@lists.icinga.org https://lists.icinga.org/mailman/listinfo/icinga-users
