[Linux-cluster] Cman (and corosync) starting before network interface is ready

[Andrew Beekhof]

On 18 Sep 2014, at 12:34 am, Vallevand, Mark K <Mark.Vallevand at UNISYS.com> wrote:

> Thanks.
> 
> 1. I didn't know about two-node mode.  Thanks.  We are testing with two nodes and "crm configure property no-quorum-policy=ignore".  When one node goes down, the other node continues clustering.  This is the desired behavior.  What will <cman two_node="1" expected_votes="1"> </cman> in cluster.conf do?

I was all set to be a smart-ass and say 'man cluster.conf', but the joke is on me as my colleagues do not appear to have documented it anywhere.
Chrissie: Can you elaborate on the details here please?

(Short version, it should do what you want)

> 2. Yes, fencing is part of our plan, but not at this time.  In the configurations we are testing, fencing is a RFPITA.
> 3. We could move up.  We like Ubuntu 12.04 LTS because it is Long Term Support.  But, we've upgraded packages as necessary.  So, if we move to the latest stable Pacemaker, Cman and Corosync (and others?), how could this help?

Well you might get 3+ years of bug fixes and performance improvements :-)

> 
> Is there a way to get the clustering software to 'poll' faster?  I mean, this NIC stalling at boot time only lasts about 2 seconds beyond the start of corosync.  But, its 30 more seconds before the nodes see each other.  I see lots of parameters in the totem directive that seem interesting.  Would any of them be appropriate.

Is there not a way to tell upstart not to start the cluster until the network is up?

> 
> Andrew: Thanks for the prompt response.
> 
> 
> Regards.
> Mark K Vallevand
> 
> "If there are no dogs in Heaven, then when I die I want to go where they went." 
> -Will Rogers
> 
> THIS COMMUNICATION MAY CONTAIN CONFIDENTIAL AND/OR OTHERWISE PROPRIETARY MATERIAL and is thus for use only by the intended recipient. If you received this in error, please contact the sender and delete the e-mail and its attachments from all computers.
> 
> 
> -----Original Message-----
> From: linux-cluster-bounces at redhat.com [mailto:linux-cluster-bounces at redhat.com] On Behalf Of Andrew Beekhof
> Sent: Tuesday, September 16, 2014 08:51 PM
> To: linux clustering
> Subject: Re: [Linux-cluster] Cman (and corosync) starting before network interface is ready
> 
> 
> On 17 Sep 2014, at 7:20 am, Vallevand, Mark K <Mark.Vallevand at UNISYS.com> wrote:
> 
>> It looks like there is some odd delay in getting a network interface up and ready.  So, when cman starts corosync, it can't get to the cluster.  So, for a time, the node is a member of a cluster-of-one.  The cluster-of-one begins starting resources.
> 
> 1. enable two-node mode in cluster.conf (man page should indicate where/how) then disable no-quorum-policy=ignore
> 2. configure fencing
> 3. find a newer version of pacemaker, we're up to .12 now
> 
>> A few seconds later, when the interface finally is up and ready, it takes about 30 more seconds for the cluster-of-one to finally rejoin the larger cluster.  The doubly-started resources are sorted out and all ends up OK.
>> 
>> Now, this is not a good thing to have these particular resources running twice.  I'd really like the clustering software to behave better.  But, I'm not sure what 'behave better' would be.
>> 
>> Is it possible to introduce a delay into cman or corosync startup?  Is that even wise?
>> Is there a parameter to get the clustering software to poll more often when it can't rejoin the cluster?
>> 
>> Any suggestions would be welcome.
>> 
>> Running Ubuntu 12.04 LTS.  Pacemaker 1.1.6.  Cman 3.1.7.  Corosync 1.4.2.
>> 
>> Regards. 
>> Mark K Vallevand
>> "If there are no dogs in Heaven, then when I die I want to go where they went."
>> -Will Rogers
>> 
>> THIS COMMUNICATION MAY CONTAIN CONFIDENTIAL AND/OR OTHERWISE PROPRIETARY MATERIAL and is thus for use only by the intended recipient. If you received this in error, please contact the sender and delete the e-mail and its attachments from all computers.
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