[Pacemaker] asymmetric clusters, remote nodes, and monitor operations

[Lindsay Todd]

We've been attempting to set up an asymmetric pacemaker cluster using
remote cluster nodes, with pacemaker 1.1.10 (actually, building from git
lately, currently at a4eb44f).  We use location constraints to enable
resources to start on nodes they should start on, and rely on asymmetry to
otherwise keep resources from starting.

But we get many monitor operation failures.

Resource monitor operations run on the physical real hosts, and frequently
fail because not all the components are present on those hosts.  For
instance, the mysql resource agent's monitor operation fails as "not
installed", since, well, mysql isn't installed on those systems, so the
validate operation, which most or every path through that agent runs,
always fails.  I don't see failures on the remote nodes, even ones without
mysql installed.

Previously I'd noticed LSB resources had failed monitor operations on
systems that didn't have the LSB init script installed.

Presumably these monitor operations are happening to ensure the resource is
NOT running where it should not be???  There doesn't seem to be a way to
set up location constraints to prevent this from happening, at least that
I've found.  I wrote an OCF wrapper RA to help me with LSB init scripts,
but not sure what to do about other RA's like mysql short of maintaining my
own version, unless there is a way to tune where "monitor" runs.  Or more
likely I'm missing something ...

It would seem to me that a "not installed" failure, OCF_ERR_INSTALLED,
would not really be an error on a node that shouldn't be running that
resource agent anyway, and is probably a pretty good indication that it
isn't running.

/Lindsay
-------------- next part --------------
An HTML attachment was scrubbed...
URL: <https://lists.clusterlabs.org/pipermail/pacemaker/attachments/20130903/94eeb4ad/attachment-0003.html>