[Pacemaker] Does pingd works on openais?

[Lars Marowsky-Bree]

On 2008-03-07T20:11:46, Atanas Dyulgerov <atanas.dyulgerov at postpath.com> wrote:

> Hm, I left with the impression openais is part of the red hat cluster suite in some way: http://sources.redhat.com/cluster/faq.html#what

Check question 12 ;-)

> >That's something the resource agents would need to do. And as far as I
> >know, openAIS does not do the resource level locking you refer to; but
> >Pacemaker internally ensures exclusive access to them.
> Yes, Pacemaker should support resource locking.

But it does. Pacemaker already "locks" the resources to one node, and
orders fencing, STONITH, start/stop etc as needed to ensure that
resources are not running where they aren't allowed to.That's what a
cluster resource manager is all about.

I'm not sure what more you are asking for?

> So you are saying that Heartbeat replaces successfully all of the above? Can OCFS2 get its membership information from Heartbeat? Does Heartbeat CRM controls OCFS2 distributed lock manager?
> 
> If true, could you send me some links for that? Patches, docs, sample configuration in Heartbeat? Thanks!

We've got that working in SLES10. The patches are all open source (of
course), and the user-space membership code is supposedly merged
upstream in OCFS2 by now.

On the heartbeat/Pacemaker side, it is as easy as configuring the
Filesystem resource for the ocfs2 mount, just as a clone.

> >That is going to work just fine, though if you're using GFS2 or OCFS2 on
> >top of GNBD or iSCSI (because you don't have a SAN, presumably), I'd
> >really wonder why you're not directly using NFS?
> Hm? GFS and GNBD works with red hat cluster suite only?

GFS yes; GFS2 will eventually work with Pacemaker as well.

> I don't have SAN. I'm looking for a cheaper solution. The reason I'm
> not using NFS is the slower performance compared to the fastest GNBD
> and iSCSI.

Have you _benchmarked_ that for your workload? iSCSI/GNBD are
block-level protocols, that means a higher overhead over the network.
And because OCFS2/GFS2 do their own locking, the nodes also have a fair
bit of additional internode communication.

> Also a very specific service application is running on the cluster and
> it does not get along with NFS very well.

What kind of features does it use that don't get along with NFS? In
theory, NFSv4/3 should be 1:1 compatible?

> To lock the network block device if node fails to bring down the
> service application or if for any reason the cluster software fails on
> that node. In that case the application will be started on a passive
> node and the cluster might end up with two nodes which try to access
> the same data.

Pacemaker/Heartbeat handle this through fencing/STONITH. It'd of course
be fatal if not.

> >> 	- OCFS2 is not completely stable and it is driven by its own cluster 
> >OCFS2 is not completely stable?
> That's what I read on various forums... not my personal experience.

Ah. Rumors. ;-)



Regards,
    Lars

-- 
Teamlead Kernel, SuSE Labs, Research and Development
SUSE LINUX Products GmbH, GF: Markus Rex, HRB 16746 (AG Nürnberg)
"Experience is the name everyone gives to their mistakes." -- Oscar Wilde