[Pacemaker] Should monitor operations be stopped after a resource is unmanaged?

[Ron Kerry]

On 7/22/64 2:59 PM, Serge Dubrouski wrote:
> On Fri, Apr 1, 2011 at 2:09 PM, Ron Kerry <rkerry at sgi.com> wrote:
>  > On 7/22/64 2:59 PM, Pavel Levshin wrote:
>  >>
>  >> 01.04.2011 18:36, Ron Kerry:
>  >> > Folks -
>  >> >
>  >> > Consider a running cluster with all resources managed. We want to stop
>  >> > and quickly restart a particular resource without impacting other
>  >> > resources. The software stack running on the system can deal with this
>  >> > sort of temporary outage. We perform the following actions:
>  >> > * unmanage the resource
>  >> > * stop the resource
>  >> > * start the resource
>  >> > * manage the resource
>  >> >
>  >> > The above procedure is sometimes successful. However, we will also
>  >> > sometimes get a resource monitor failure after stopping the resource.
>  >> > It is clear that the monitor operation was not stopped (at least not
>  >> > immediately) by unmanaging the resource.
>  >>
>  >> Unmanaged resource cannot be started and stopped, but can still be
>  >> monitored.
>  >
>  > So unmanaged really means the resource is still being managed to some
>  > degree?
>
> It means that Pacemaker still wants to know its state. What kind of
> problem does it create?
>

An unmanaged resource whoose monitor is still running will cause a monitor failure when the resource 
is stopped. Pacemaker then takes the 'onfail' action defined for the monitor operation. In other 
words, the resource is still being managed to some degree. If the monitor operation was still 
running but no action was taken as a result of the monitor operation outcome, there would be no issue.

-- 

Ron Kerry         rkerry at sgi.com