[ClusterLabs] resource management of standby node

[Roger Zhou]

On 12/1/20 4:03 PM, Ulrich Windl wrote:
>>>> Ken Gaillot <kgaillot at redhat.com> schrieb am 30.11.2020 um 19:52 in Nachricht
> <f3c9daaca84fea2c0db99c5ae161e4785e75a802.camel at redhat.com>:
> 
> ...
>>
>> Though there's nothing wrong with putting all nodes in standby. Another
>> alternative would be to set the stop-all-resources cluster property.
> 
> Hi Ken,
> 
> thanks for the valuable feedback!
> 
> I was looking for that, but unfortunately crm shell cannot set that from the resource (or node) context; only from the configure context.
> I don't know what a good syntax would be "resource stop all" / "resource start all" or "resource stop-all" / "resource unstop-all"
> (the asymmetry is that after a "stop all" you cannot start a singly resource (I guess), but you'll have to use "start-all" (which, in turn, does not start resources that have a stopped role (I guess).
> 
> So maybe "resource set stop-all" / "resource unset stop-all" / "resource clear stop-all"
> 

1.
Well, let `crm resource stop|start all` change the cluster property of 
`stop-all-resources` might contaminate the syntax at the resources level alone. 
To avoid that, the user interface need be more carefully to deliver the proper 
information at the first place about the internals at some degree to avoid the 
potential misunderstanding or questions.

2.
On the other hand, people might naturally read `crm resource stop all` as 
changing all resources `target-role=Stopped`. Well, technically this seems a 
bit awkward, but no obvious benefit comparing to stop-all-resources. And, 
pacemaker developers could comment more internals around this.

3.
`resource set|unset` add more commands under `resource` and will confuse some 
users and should be avoided in my view.

I feel more discussion is expected, though my gut feeling approach 1 is a 
better one.

Anyway, good topic indeed. Feedback from more users would be useful to shape 
the better UI/UX. I can imagine some people may have idea to suggest "--all" 
even, btw.

Thanks,
Roger