On 11/08/2016 11:40 AM, Kostiantyn Ponomarenko wrote: > Hi, > > I need a way to do a manual fail-back on demand. > To be clear, I don't want it to be ON/OFF; I want it to be more like > "one shot". > So far I found that the most reasonable way to do it - is to set > "resource stickiness" to a different value, and then set it back to > what it was. > To do that I created a simple script with two lines: > > crm configure rsc_defaults resource-stickiness=50 > crm configure rsc_defaults resource-stickiness=150 > > There are no timeouts before setting the original value back. > If I call this script, I get what I want - Pacemaker moves resources > to their preferred locations, and "resource stickiness" is set back to > its original value. > > Despite it works, I still have few concerns about this approach. > Will I get the same behavior under a big load with delays on systems > in cluster (which is truly possible and a normal case in my environment)? > How Pacemaker treats fast change of this parameter? > I am worried that if "resource stickiness" is set back to its original > value to fast, then no fail-back will happen. Is it possible, or I > shouldn't worry about it?
AFAIK pengine is interrupted when calculating a more complicated transition and if the situation has changed a transition that is just being executed is aborted if the input from pengine changed. So I would definitely worry! What you could do is to issue 'crm_simulate -Ls' in between and grep for an empty transition. There might be more elegant ways but that should be safe. > Thank you, > Kostia > > > _______________________________________________ > Users mailing list: [email protected] > http://clusterlabs.org/mailman/listinfo/users > > Project Home: http://www.clusterlabs.org > Getting started: http://www.clusterlabs.org/doc/Cluster_from_Scratch.pdf > Bugs: http://bugs.clusterlabs.org _______________________________________________ Users mailing list: [email protected] http://clusterlabs.org/mailman/listinfo/users Project Home: http://www.clusterlabs.org Getting started: http://www.clusterlabs.org/doc/Cluster_from_Scratch.pdf Bugs: http://bugs.clusterlabs.org
