[ClusterLabs] Preventing multiple resources from moving at the same time.

[Klaus Wenninger]

On 4/20/21 11:43 PM, Ken Gaillot wrote:
> On Tue, 2021-04-20 at 13:43 -0700, Matthew Schumacher wrote:
>> I have a resource that more or less makes or breaks everything
>> (storage).
>>
>> When I move it, it only takes a few seconds and everything keeps
>> working
>> due to timeouts, however, if another resource tries to migrate/move
>> at
>> the same time it will break and causes an outage.
Just to better understand the issue ...
Does the first resource implement storage that is being used
by the resource that is being migrated/moved?
Or is it just the combination of 2 parallel moves that is
overcommitting storage or network?
Is it assured that there are no load-scenarios inside these
resources that create the same issues as if you migrate/move
them?

Klaus
>>
>> Is there any way to define a resource group in such a way where if
>> it's
>> in the process of being moved, don't move anything else no matter
>> what?
>>
>> Thanks,
>> Matt
> I think the closest thing is an optional ordering. If A is ordered
> after B optionally, and both have to move, A will stop, then B will
> stop, then B will start, then A will start. If only B has to move, it
> won't force A to restart.