[ClusterLabs] Using pacemaker for manual failover only?

[Ken Gaillot]

On 05/24/2016 04:13 AM, Klaus Wenninger wrote:
> On 05/24/2016 09:50 AM, Jehan-Guillaume de Rorthais wrote:
>> Le Tue, 24 May 2016 01:53:22 -0400,
>> Digimer <lists at alteeve.ca> a écrit :
>>
>>> On 23/05/16 03:03 PM, Stephano-Shachter, Dylan wrote:
>>>> Hello,
>>>>
>>>> I am using pacemaker 1.1.14 with pcs 0.9.149. I have successfully
>>>> configured pacemaker for highly available nfs with drbd. Pacemaker
>>>> allows me to easily failover without interrupting nfs connections. I,
>>>> however, am only interested in failing over manually (currently I use
>>>> "pcs resource move <drbd_rsc> <target_node> --master"). I would like for
>>>> the cluster to do nothing when a node fails unexpectedly.
>>>>
>>>> Right now the solution I am going with is to run 
>>>> "pcs property set is-managed-default=no"
>>>> until I need to failover, at which point I set is-managed-default=yes,
>>>> then failover, then set it back to no.
>>>>
>>>> While this method works for me, it can be unpredictable if people run
>>>> move commands at the wrong time.
>>>>
>>>> Is there a way to disable automatic failover permanently while still
>>>> allowing manual failover (with "pcs resource move" or with something else)?
>> Try to set up your cluster without the "interval" parameter on the monitor
>> action? The resource will be probed during the target-action (start/promote I
>> suppose), but then it should not get monitored anymore.
> 
> Ignoring the general cluster yes/no question a simple solution would
> be to bind the master-role to a node-attribute that you move around
> manually.

This is the right track. There are a number of ways you could do it, but
the basic idea is to use constraints to only allow the resources to run
on one node. When you want to fail over, flip the constraints.

I'd colocate everything with one (most basic) resource, so then all you
need is one constraint for that resource to flip. It could be as simple
as a -INFINITY location constraint on the node you don't want to run on.