[ClusterLabs] How Pacemaker reacts to fast changes of the same parameter in configuration

[Kostiantyn Ponomarenko]

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?

Thank you,
Kostia
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