[Linux-cluster] Re: Re: Re: CS4 : problem with multiple IP addresses (cont.)

[Patrick Caulfield]

Alain Moulle wrote:
> Hi
> I don't really know if it is a bug, but the problem occurs when
> you a DNS is used, and when a node must be reachable from two
> different networks but with the same name on both networks; in this
> case, the gethostbyname() returns (from DNS) more than one adress for
> a Node name. So it seems that this leads to set the Node Name in cluster.conf
> as an IP addr. OK ?
> So, the bug is perhaps more to have to launch cman service with a specific
> syntax and no more by "service cman start" ... the cman start should manage
> by itself the two modes for node name in cluster.conf : name or IP addr.
> Do you agree ?

The problem is that cman needs an unambiguous name and IP address for
its communication. If the IP address maps to >1 name or the name maps to
>1 IP then it can't do this.

What I would do in this situation (and I've just been playing with it)
is to define /another/ non-ambiguous name that's only used for the
cluster and start the service with cman_tool join -n <newname>.

Functionally, that's identical to using the IP address of course, but
it's a little easier on the eye in cman_tool nodes output !

I agree it should be settable via a variable available to the startup
script. (it's easy enough to edit that script but you need to be careful
of upgrades)

Patrick