[Openais] separate interfaces as separate nodes?

[Fredrik Arnerup]

Well, suppose you have two servers (A and B), each with two interfaces (1 &
2).
Now, one of these four interfaces needs to be the master and hold the
virtual ip.
Let's say A1 is master and then the A1 interface goes down.
Neither A nor B will notice that A1 is down because B is still reachable via
A2.

I suppose A could use netlink to detect that A1 is down and switch to A2.
(That won't work if the problem is at a switch, although admittedly, it is
unlikely for 1 and 2 to be connected to different switches.)

I thought it would be simpler to treat each interface as a separate node.
Of course, then you would have to make sure that traffic between 1 and 2
isn't routed internally.

/Fredrik

-----Original Message-----
From: Steven Dake [mailto:sdake at redhat.com] 
Sent: Thursday, August 19, 2010 8:19 PM
To: Fredrik Arnerup
Cc: openais at lists.linux-foundation.org
Subject: Re: [Openais] separate interfaces as separate nodes?

On 08/19/2010 05:34 AM, Fredrik Arnerup wrote:
> Hi,
>
> I'm trying to build an cluster using machines which have two network 
> interfaces each.
> In order to handle load balancing over all working interfaces in the 
> cluster I would need to treat each interface as a separate node.
>
> Is this possible to do with corosync?
> If I have two interface directives in corosync.conf, they are still 
> treated as the same node, right?
yes this is right

> I suppose it isn't possible to run two instances of corosync on the 
> same machine.

No, in fact recently we just forced corosync to run only one instance per
node.

I'm not clear on your use case.  Why would you want two cluster instances on
one node?  Just to detect for NIC device outtage on one of the devices?

Regards
-steve

>
> /Fredrik Arnerup
>
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