[Linux-HA] Two instances of ldirectord?

[Simon Horman]

On Mon, Mar 08, 2010 at 09:44:09PM +0100, Michael Schwartzkopff wrote:
> Am Montag, 8. März 2010 21:38:04 schrieb Ciro Iriarte:
> > 2010/3/8 Michael Schwartzkopff <misch at multinet.de>:
> > > Am Montag, 8. März 2010 20:04:53 schrieb Ciro Iriarte:
> > >> Would it be possible to run two instances of ldirectord in a cluster?,
> > >> my concern is that if both resources are running on the same node and
> > >> are later migrated to other node (ldirectord-A stops), wouldn't that
> > >> wipe the LVS rules used by ldirectord-B also?.
> > >>
> > >> Or should I run the ldirectord as a clone in both machines with all
> > >> the rules and just move the VIPs between nodes?
> > >>
> > >> Regards,
> > >
> > > Hi,
> > >
> > > I think that would not be possible. But you have to check it. Anyway, I
> > > woudn't do it because one director should be enought to deal with the
> > > whole traffic. You also could configure several virtual servers on one
> > > ldirector. So no need to split it up.
> > >
> > > Greetings,
> > >
> > > --
> > > Dr. Michael Schwartzkopff
> > > MultiNET Services GmbH
> >
> > I'm asking that because at first sight it seemed possible
> > (configuration file is a parameter for the resource).
> 
> In know. I wrote it.
> 
> > The idea is just
> > to give "peace of mind" to management, as having two VIPs for two
> > different farms will help not having and idle machine in a two-node
> > LVS cluster :P
> >
> > Regards,
> 
> Yes. The problem might be that the second ldirectord erases the
> configuration of the first server in case of a failure of the second node
> and both run on the same machine. You have to check this.

This should not be a problem so long as the two configurations don't
include common virtual-services. In a nutshell, an instance of ldirectord
knows which virtual-services it is managing and only manipulates their
configuration using ipvsadm.

So to answer the original question, it should be fine to run two instances
of ldirectord.