[ClusterLabs] Antw: Re: set node in maintenance - stop corosync - node is fenced - is that correct ?

[Ulrich Windl]

>>> Ken Gaillot <kgaillot at redhat.com> schrieb am 16.10.2017 um 22:57 in Nachricht
<1508187437.6286.7.camel at redhat.com>:
> On Mon, 2017-10-16 at 21:49 +0200, Lars Ellenberg wrote:
>> On Mon, Oct 16, 2017 at 09:20:52PM +0200, Lentes, Bernd wrote:
>> > ----- On Oct 16, 2017, at 7:38 PM, Digimer lists at alteeve.ca wrote:
>> > > On 2017-10-16 01:24 PM, Lentes, Bernd wrote:
>> > > > i have the following behavior: I put a node in maintenance
>> > > > mode, afterwards stop
>> > > > corosync on that node with /etc/init.d/openais stop.
>> > > > This node is immediately fenced. Is that expected behavior ? I
>> > > > thought putting a
>> > > > node into maintenance does mean the cluster does not care
>> > > > anymore about that
>> > > > node.
>> > OS is SLES 11 SP4. That's not the most recent one.
>> > Pacmekaer is 1.1.12.
>> > I didn't plan to remove the node, but to do some maintenance on it.
>> > 
>> > If i put the node in standby, then i can invoke
>> > "/etc/init.d/openais
>> > stop" without that node getting fenced.
>> > But then all resources on that node are stopped/migrated. If i
>> > don't
>> > want that, i thought maintenance is the right way.
>> > Am i wrong ?
>> > 
>> > Ah, i just saw that i wasn't complete clear. The node is fenced
>> > after
>> > stopping openais, not after putting it into maintenance.
>> > I did that via "crm node maintenance <node>"
>> 
>> from the Changelog:
>> 
>> Changes since Pacemaker-1.1.15
>>   ...
>>   + pengine: do not fence a node in maintenance mode if it shuts down
>> cleanly
>>   ...
>> 
>> just saying ... may or may not be what you are seeing.
>> 
>> Short term "workaround" may be to do things differently.
>> Maybe just set the cluster wide maintenance mode, not per node?
> 
> Sounds right.
> 
> Another thing to keep in mind is that even if pacemaker doesn't fence
> the node, if you use DLM, DLM might fence the node (it doesn't know
> about or respect any pacemaker maintenance/unmanaged settings).
> 
> I'd stop pacemaker before stopping corosync, in any case. In
> maintenance mode, that should be fine. I don't think a running
> pacemaker would be able to reconnect to corosync after corosync comes
> back.

In SLES11 "rcopenais stop" stops pacemaker, corosync, and SBD in that order.

> 
>> What are you really trying to do,
>> what is the reason you need it in maintenance-mode
>> and stop pacemaker/corosync/openais/the clusterstack,
>> but do not want to stop/migrate off the resources,
>> as would be done with "standby"?
>> 
> -- 
> Ken Gaillot <kgaillot at redhat.com>
> 
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