[Pacemaker] Monitor a resource without the cluster reacting to the result...

[Joe Bill]

--- On Fri, 3/27/09, Andrew Beekhof <beekhof at gmail.com> wrote:

>>> I saw later that you want to prevent the cluster
>>> from doing anything for the resource, simply set
>>> is-managed=false for the resource in question. 

>> This is incorrect. I want the cluster to react to
>> everything BUT to this specific invocation of MONITOR.

>
> Then I don't understand what the purpose of the monitor is as there
> will be no other actions for the resource until the monitor completes. 

Sorry my answer above was incomplete, I just tried to counter-point your statement above it.

What I would expect is for my "mostly harmless" monitor operation to have the same "blocking" effect, at least on other monitoring operations, as a "fully effective" monitor operation. No more, no less.

What happens if I manually issue a "target role=stopped" on a resource while it's "is managed=true" and a monitor operation is running ?

Will the cluster interrupt/kill the currently running monitor operation before invoking the stop resource operation ?

I suppose no.

Will the cluster let the currently running monitor operation complete by itself, and only then invoke the stop resource operation ?

I suppose yes, while the monitor operation hasn't reached it's timeout.

Now I would expect that once ***any*** monitoring operation reached its timeout, the cluster would kill it, wouldn't it ?

And this whether a resource "stop" is pending or not.

Do you confirm ?

>> Won't the cluster NEVER interrupt an ongoing
>> MONITOR operation beyond a certain amount of time ?

> Two actions will absolutely never be concurrently
> performed for a single resource.
> This is enforced by the lrmd.

That is why I would expect the cluster to ***interrupt*** the ongoing MONITOR operation once the timeout has been reached, no ?

>> Also what happens if, while a MONITOR operation
>> is going on, I issue a:
>> "crm_resource -M" on the same resource to migrate it ?
>>
>> Will the cluster wait until the monitor operation is finished ?

> Clearly it must.
> Otherwise the monitor would fail. 

At this point, if a "crm_resource -M" was issued and the resource migration is pending, who cares about the completion status of the ongoing MONITOR function ? Who cares that it even completes at all ?


Best regards.