Hi, On Tue, May 27, 2008 at 08:53:27AM -0700, Joe Bill wrote: > Would it be possible to have an execution flow diagram > of what calls to a resource's RA HB performs, and if > it depends on the resource's state itself ? > > Typically, I assume that HB *always* performs a > 'monitor check-level 0' operation *before* performing > a 'start' or a 'stop'. > Is this correct ?
Not always. The cluster (crm) keeps track of the status. If it doesn't know the status of a particular resource then it would do a probe (i.e. a monitor op) to check it. For example, that happens when a node starts. Or after the resource has been taken out of the unmanaged mode. Hence, it is very wrong to mess with the resource without letting the cluster know. Though there's also an external program (crm_resource) which may be used to ask the crm to refresh the state of the resource (option -P). > I also assume that HB performs a 'monitor check-level > 0' *after* a successful "start" or "stop". > Is this correct ? No. If the RA exits with success (0) the action's considered to have been successful. (Hmm, how does that sound :) > Or, I assume that, if HB performs a 'monitor > check-level 0', and that operation returns a "ERROR" > status, HB automatically performs another 'monitor' of > the same resource but with the next check-level known > by HB, provided such a check-level (i.e. 10 and 20) > have been previously declared (configured) for the > resource's monitoring, until a monitoring operation > returns a clear "STARTED" or "STOPPED" status. > Is this correct ? No. > Or does HB perform "monitor" operations at *all* check > levels regardless of the status returned, of course > outside the periodic programming of monitoring > functions ? Various check levels are done only periodically and only when they are defined (and enabled) for a resource. > Also, outside of the periodic monitoring at those > different check-levels configured, HB does not perform > a higher check-level monitoring operation if one > monitoring operation returns a "STARTED" or "STOPPED" > status, and that status matches what HB believes is > the current status for that resource. No. All monitor operations are carried out when they are scheduled. If any of them results in a failure (or reports that the resource is not running) some action may be taken immediately (typically failover or restart). Thanks, Dejan > Is this correct ? > Thank you for your replies. > Is > > > > _______________________________________________ > Linux-HA mailing list > [email protected] > http://lists.linux-ha.org/mailman/listinfo/linux-ha > See also: http://linux-ha.org/ReportingProblems _______________________________________________ Linux-HA mailing list [email protected] http://lists.linux-ha.org/mailman/listinfo/linux-ha See also: http://linux-ha.org/ReportingProblems
