[Pacemaker] high cib load on config change

[James Harper]

> > I guess I'd first like to know if the log entries I was seeing ("Failed
> > application of an update diff" and "Requesting re-sync from peer") means
> > that a full resync is being done, and if that's a problem or not.
> 
> There are occasions when its not a problem, but I don't think any of them
> apply to you.
> 
> Questions:
> - are you making any config changes when this behaviour is occurring?

Yes. This is when the problem occurs (eg adding a location to a resource)

> - if so, from one node only or many?

>From any node, but only one at a time (I think that's what you are asking).

> - what version is this?  1.1.7 or 1.1.7 plus some debian patches? which
> patches?

1.1.7 packaged by Debian, and possibly patched by Debian. I'll follow this up. I just noticed that some of my nodes are running corosync (again, Debian packages) 1.4.4-2 and others are running 1.4.2-3. I wonder if there is something in that...

I just built a 5 node cluster on virtual machines with my problematic configuration (with all resources changed to Dummy) and while there is high CPU load on a change, I don't know that it's as bad as my actual cluster, especially as all 5 virtual machines are running on the one physical machine (which is the same physical machine that feels the load problem the worst). There are no "Failed application of an update diff" messages either.

Thanks

James