[ClusterLabs] Maintenance mode status in CIB

[Digimer]

On 2020-10-13 4:32 a.m., Jehan-Guillaume de Rorthais wrote:
> On Mon, 12 Oct 2020 19:08:39 -0400
> Digimer <lists at alteeve.ca> wrote:
> 
>> Hi all,
> 
> Hi you,
> 
>>
>>   I noticed that there appear to be a global "maintenance mode"
>> attribute under cluster_property_set. This seems to be independent of
>> node maintenance mode. It seemed to not change even when using
>> 'pcs node maintenance --all'
> 
> You can set maintenance-mode using:
> 
>   pcs property set maintenance-mode=true
> 
> You can read about "maintenance-mode" cluster attribute and "maintenance" node
> attribute in chapters:
> 
>   https://clusterlabs.org/pacemaker/doc/en-US/Pacemaker/2.0/html/Pacemaker_Explained/s-cluster-options.html 
>   https://clusterlabs.org/pacemaker/doc/en-US/Pacemaker/2.0/html/Pacemaker_Explained/_special_node_attributes.html
> 
> I would bet the difference is that "maintenance-mode" applies to all nodes in
> one single action. Using 'pcs node maintenance --all', each pcsd daemon apply
> the local node maintenance independently. 
> 
> With the later, I suppose you might have some lag between nodes to actually
> start the maintenance, depending on external factors. Moreover, you can
> start/exit the maintenance mode independently on each nodes.

Thanks for this.

A question remains; Is it possible that:

<nvpair id="cib-bootstrap-options-maintenance-mode"
name="maintenance-mode" value="false"/>

Could be set, and a given node could be:

<node id="1" uname="mk-a02n01">
  <instance_attributes id="nodes-1">
    <nvpair id="nodes-1-maintenance" name="maintenance" value="off"/>
  </instance_attributes>
</node>

That is to say; If the cluster is set to maintenance mode, does that
mean I should consider all nodes to also be in maintenance mode,
regardless of what their individual maintenance mode might be set to?

-- 
Digimer
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