[ClusterLabs] What's a "transition", BTW?

[Ulrich Windl]

Hi!

With a cluster recheck interval, I see periodic log messages like this:
Jan 15 11:05:50 h19 pacemaker-controld[4804]:  notice: State transition S_TRANSITION_ENGINE -> S_IDLE
Jan 15 11:15:50 h19 pacemaker-controld[4804]:  notice: State transition S_IDLE -> S_POLICY_ENGINE
Jan 15 11:15:50 h19 pacemaker-schedulerd[4803]:  notice: Watchdog will be used via SBD if fencing is required and stonith-watchdog-timeout is nonzero
Jan 15 11:15:50 h19 pacemaker-schedulerd[4803]:  notice: Calculated transition 596, saving inputs in /var/lib/pacemaker/pengine/pe-input-41.bz2
Jan 15 11:15:50 h19 pacemaker-controld[4804]:  notice: Processing graph 596 (ref=pe_calc-dc-1610705750-978) derived from /var/lib/pacemaker/pengine/pe-input-41.bz2
Jan 15 11:15:50 h19 pacemaker-controld[4804]:  notice: Transition 596 (Complete=3, Pending=0, Fired=0, Skipped=0, Incomplete=0, Source=/var/lib/pacemaker/pengine/pe-input-41.bz2): Complete

The "transition" number increases each time, while there is visible no action to be performed. So what's in such a "transition"? Couldn't the cluster skip those lines if there's nothing to do?

Regards,
Ulrich