[ClusterLabs] Coming in Pacemaker 1.1.17: start a node in standby

[Jehan-Guillaume de Rorthais]

On Tue, 25 Apr 2017 10:02:21 +0200
Lars Ellenberg <lars.ellenberg at linbit.com> wrote:

> On Mon, Apr 24, 2017 at 03:08:55PM -0500, Ken Gaillot wrote:
> > Hi all,
> > 
> > Pacemaker 1.1.17 will have a feature that people have occasionally asked
> > for in the past: the ability to start a node in standby mode.  
> 
> 
> I seem to remember that at some deployment,
> we set the node instance attribute standby=on, always,
> and took it out of standby using the node_state transient_attribute :-)
> 
> As in
> # crm node standby ava
>   <node id="1" uname="ava">
>     <instance_attributes id="nodes-1">
>       <nvpair id="nodes-1-standby" name="standby" value="on"/>
>       ...
>     </instance_attributes>
>   </node>
>   ...

This solution seems much more elegant and obvious to me. A cli
(crm_standby?) interface would be ideal.

It feels weird to mix setup interfaces (through crm_standby or through the
config file) to manipulate the same node attribute. Isn't it possible to set
the standby instance attribute of a node **before** it is added to the cluster?

> # crm node status-attr ava set standby off
>   <node_state id="1" uname="ava" in_ccm="true" crmd="online"
> crm-debug-origin="do_update_resource" join="member" expected="member"> ...
>     <transient_attributes id="1">
>       <instance_attributes id="status-1">
> 	...
>         <nvpair id="status-1-standby" name="standby" value="off"/>
>       </instance_attributes>
>     </transient_attributes>
>   </node_state>

It is not really straight forward to understand why you need to edit a second
different nvpair to exit the standby mode... :/