[ClusterLabs] Antw: [EXT] Load balancing, of a sort

[Ulrich Windl]

>>> Antony Stone <Antony.Stone at ha.open.source.it> schrieb am 25.01.2023 um
13:48 in
Nachricht <202301251348.58372.Antony.Stone at ha.open.source.it>:
> Hi.
> 
> I have a corosync / pacemaker 3-node cluster with a resource group which can

> 
> run on any node in the cluster.
> 
> Every night a cron job on the node which is running the resources performs 
> "crm_standby -v on" followed a short while later by "crm_standby -v off" in

> order to force the resources to migrate to another node member.

Hi!

As Ken pointed out, there are more elegant ways to do that (not to talk about
more elegant ways to rotate the logs, but admittedly there are bad applications
out in the wild).

Hard to say what your cluster status exactly is, but my favourite command is
"crm_mon -1Arfj" to check ��

Regards,
Ulrich


> 
> We do this partly to verify that all nodes are capable of running the 
> resources, and partly because some of those resources generate significant 
> log 
> files, and if one machine just keeps running them day after day, we run out

> of 
> disk space (which effectively means we just need to add more capacity to the

> 
> machines, which can be done, but at a cost).
> 
> So long as a machine gets a day when it's not running the resources, a 
> combination of migrating the log files to a central server, plus standard 
> logfile rotation, takes care of managing the disk space.
> 
> What I notice, though, is that two of the machines tend to swap the 
> resources 
> between them, and the third machine hardly ever becomes the active node.
> 
> Is there some way of influencing the node selection mechanism when resources

> 
> need to move away from the currently active node, so that, for example, the

> least recently used node could be favoured over the rest?
> 
> 
> Thanks,
> 
> 
> Antony.
> 
> -- 
> I want to build a machine that will be proud of me.
> 
>  - Danny Hillis, creator of The Connection Machine
> 
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