[ClusterLabs] Speed up the resource moves in the case of a node hard shutdown

[Maxim]

13.02.2018 16:41, Klaus Wenninger пишет:
> Let's put that differently.  With fencing you can make the
 > loss-detection more aggressive and thus more prone to false-positives
 > without risking a split-brain situation. (Actually without fencing
 > you can never be really sure if the other side is really gone!) But
 > to be honest if you are really behind sub-second
 > detection/switchover I'm not sure if fencing - at least with the
 > current implementation in pacemaker and the current selection of
 > fencing-devices - will give you satisfactory results.

 > If you don't have any of the usual fencing-devices available you
 > might have some kind of a shared-disk that might be usable with SBD.
 > For a 2-node-cluster with a single shared-disk (as in your case if I
 > got it correctly) assure to pick an SBD-version that has
 > 
https://github.com/ClusterLabs/sbd/commit/4bd0a66da3ac9c9afaeb8a2468cdd3ed51ad3377.
 >
 > But again I doubt that this will work reliably with sub-second 
requirements.

>
 > Not saying I'm not interested in experiences/requirements with
 > pacemaker doing failovers in a sub-second or more relaxed
 > low-single-digit-second timeframe. Seeing this working reliably would
 > open up pacemaker for a completely new class of applications.
 >
 > Regards, Klaus

I was in a sceptical mind too... especially when i've seen the monitor 
intervals of pacemaker resource agents :D
So <1 sec timings for an issue_detection & resource_moves seems are 
unachiavable by facilities of the current cluster software. By the 
architectural reasons as well.

Thank you for the support and proposals.