[Pacemaker] Speed up resource failover?

[Robert van Leeuwen]

-----Original message-----
To:	pacemaker at oss.clusterlabs.org; 
From:	Patrick H. <pacemaker at feystorm.net>
Sent:	Wed 12-01-2011 00:06
Subject:	[Pacemaker] Speed up resource failover?
Attachment:	inline.txt
> As it is right now, pacemaker seems to take a long time (in computer terms) to 
> fail over resources from one node to the other. Right now, I have 477 IPaddr2 
> resources evenly distributed among 2 nodes. When I put one node in standby, it 
> takes approximately 5 minutes to move the half of those from one node to the 
> other. And before you ask, theyre because of SSL http virtual hosting. I have 
> no order rules, colocations or anything on those resources, so it should be 
> able migrate the entire list simultaneously, but it seems to do them 
> sequentially. Is there any way to make it migrate the resources in parallel? Or 
> at the very least speed it up?

Patrick,

It's probably not so much the cluster suite but is has to do with the specific resource script. 
For a proper takeover of a IP you have to do an arp "deregister/register".
This will take a few seconds.
As long as a resource script is busy the cluster suite will not start the next action.
Parallel execution is not possible in the cluster suite as far as I know.
(without being a programmer myself I would expect it is pretty tricky to implement parallelization "code-wise" and making 100% sure the cluster does not break)

You could consider to edit the IPaddr2 resource script so it does not wait for the arp commands.
At you're own risk of course ;-)

Kind regards,
Robert van Leeuwen