>>> Andrei Borzenkov <arvidj...@gmail.com> schrieb am 11.04.2021 um 20:20 in Nachricht <f2eb393c-52b1-af38-a684-ddd7f68d4...@gmail.com>: > On 11.04.2021 20:07, Eric Robinson wrote: >> We're writing a custom RA for a multi‑tenant MySQL cluster that runs in > active/standby mode. I've read the RA documentation about what exit codes > should be returned for various outcomes, but something is still unclear to > me. >> >> We run multiple instances of MySQL from one filesystem, like this: >> >> /app_root >> /mysql1 >> /mysql2 >> /mysql3 >> ...etc. >> >> The /app_root filesystem lives on a DRBD volume, which is only mounted on > the active node. >> >> When the RA performs a "start," "stop," or "monitor" action on the standby
> node, the filesystem is not mounted so the mysql instances are not present. > > You are not supposed to do it in the first place. You are supposed to > have ordering constraint that starts MySQL instances after filesystem is > available. But probes don't care about ordering constraints. > >> What should the return codes for those actions be? Fail? Not installed? > Unknown error? >> > > I believe that "not installed" is considered hard error and bans > resource from this node. As missing filesystem is probably transient it > does not look appropriate. There is no "fail" return code. > > In any case return code depends on action. For monitor you obviously are > expected to return "not running" in this case. "stop" should probably > return success (after all, instance is not running, right?) And "start" > should return error indication, but it I am not sure what is better ‑ > generic error or not running. > > _______________________________________________ > Manage your subscription: > https://lists.clusterlabs.org/mailman/listinfo/users > > ClusterLabs home: https://www.clusterlabs.org/ _______________________________________________ Manage your subscription: https://lists.clusterlabs.org/mailman/listinfo/users ClusterLabs home: https://www.clusterlabs.org/
