[corosync] [Pacemaker] Different Corosync Rings for Different Nodes in Same Cluster?

Dan Frincu df.cluster at gmail.com
Fri Jun 29 08:42:13 GMT 2012


Hi,

On Thu, Jun 28, 2012 at 6:13 PM, Andrew Martin <amartin at xes-inc.com> wrote:
> Hi Dan,
>
> Thanks for the help. If I configure the network as I described - ring 0 as
> the network all 3 nodes are on, ring 1 as the network only 2 of the nodes
> are on, and using "passive" - and the ring 0 network goes down, corosync
> will start using ring 1. Does this mean that the quorum node will appear to
> be offline to the cluster? Will the cluster attempt to STONITH it? Once the
> ring 0 network is available again, will corosync transition back to using it
> as the communication ring, or will it continue to use ring 1 until it fails?
>
> The ideal behavior would be when ring 0 fails it then communicates over ring
> 1, but keeps periodically checking to see if ring 0 is working again. Once
> it is, it returns to using ring 0. Is this possible?

Added corosync ML in CC as I think this is better asked here as well.

Regards,
Dan

>
> Thanks,
>
> Andrew
>
> ________________________________
> From: "Dan Frincu" <df.cluster at gmail.com>
> To: "The Pacemaker cluster resource manager" <pacemaker at oss.clusterlabs.org>
> Sent: Wednesday, June 27, 2012 3:42:42 AM
> Subject: Re: [Pacemaker] Different Corosync Rings for Different Nodes
> in        Same Cluster?
>
>
> Hi,
>
> On Tue, Jun 26, 2012 at 9:53 PM, Andrew Martin <amartin at xes-inc.com> wrote:
>> Hello,
>>
>> I am setting up a 3 node cluster with Corosync + Pacemaker on Ubuntu 12.04
>> server. Two of the nodes are "real" nodes, while the 3rd is in standby
>> mode
>> as a quorum node. The two "real" nodes each have two NICs, one that is
>> connected to a shared LAN and the other that is directly connected between
>> the two nodes (for DRBD replication). The quorum node is only connected to
>> the shared LAN. I would like to have multiple Corosync rings for
>> redundancy,
>> however I do not know if this would cause problems for the quorum node. Is
>> it possible for me to configure the shared LAN as ring 0 (which all 3
>> nodes
>> are connected to) and set the rrp_mode to passive so that it will use ring
>> 0
>> unless there is a failure, but to also configure the direct link between
>> the
>> two "real" nodes as ring 1?
>
> Short answer, yes.
>
> Longer answer. I have a setup with two nodes with two interfaces, one
> is connected via a switch to the other node and one is a back-to-back
> link for DRBD replication. In Corosync I have two rings, one that goes
> via the switch and one via the back-to-back link (rrp_mode: active).
> With rrp_mode: passive it should work the way you mentioned.
>
> HTH,
> Dan
>
>>
>> Thanks,
>>
>> Andrew
>>
>> _______________________________________________
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>> http://oss.clusterlabs.org/mailman/listinfo/pacemaker
>>
>> Project Home: http://www.clusterlabs.org
>> Getting started: http://www.clusterlabs.org/doc/Cluster_from_Scratch.pdf
>> Bugs: http://bugs.clusterlabs.org
>>
>
>
>
> --
> Dan Frincu
> CCNA, RHCE
>
> _______________________________________________
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> http://oss.clusterlabs.org/mailman/listinfo/pacemaker
>
> Project Home: http://www.clusterlabs.org
> Getting started: http://www.clusterlabs.org/doc/Cluster_from_Scratch.pdf
> Bugs: http://bugs.clusterlabs.org
>
>
> _______________________________________________
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> http://oss.clusterlabs.org/mailman/listinfo/pacemaker
>
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> Getting started: http://www.clusterlabs.org/doc/Cluster_from_Scratch.pdf
> Bugs: http://bugs.clusterlabs.org
>



-- 
Dan Frincu
CCNA, RHCE


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