[ClusterLabs] Reliable check for "is starting" state of a resource

[Ken Gaillot]

On 11/22/2016 10:53 AM, Kostiantyn Ponomarenko wrote:
> Hi folks,
> 
> I am looking for a good way of checking if a resource is in "starting"
> state.
> The thing is - I need to issue a command and I don't want to issue that
> command when this particular resource is starting. This resource start
> can take up to a few min. 
> As a note, I am OK with issuing that command if a resource is stopped
> (before it starts).
> 
> The best I can think of, is to check for an ongoing state transition of
> a resource in a loop with "crm_simulate -Ls" command.
> But with this approach I need to put the command into a loop, cut
> "Transition Summary" part, and then grep for the needed resource.
> And even that I have a question if this way is reliable?
> 
> Maybe be there is a better way of achieving the same result.  
> 
> Thank you,
> Kostia

Probably the cleanest way is to set record-pending=true (either as an
operation default, or just on the start operation you're interested in).
Then your command (or a wrapper) could check the CIB for a pending start.

A simpler approach would be "crm_resource --wait", which blocks until
the cluster is idle. The downside is you might wait for other actions
that you don't care about.