[ClusterLabs Developers] shutdown testing in pacemaker corosync cluster

Ken Gaillot kgaillot at redhat.com
Mon Nov 30 16:30:19 EST 2020


On Sun, 2020-11-29 at 14:21 +0000, Harishkumar Pathangay wrote:
> Hi,
> I am new to pace maker and learnt lot of things from documentation
> guide
> Pacemaker-2.0-Pacemaker_Administration-en-US.pdf
> Pacemaker-2.0-Pacemaker_Development-en-US
>  
> I was able to successfully create a db2 resource agent which will
> start instance when cluster starts.
> Things are not production ready, but I can reasonably say script is
> working in a 2-node cluster.
> DB2 will run in node dragon initially. But if one node goes down it
> will start db2 on other node tiger.
> Tow Nodes are Linux RHEL 7.8 – DRAGON and TIGER.
>  
> If I shutdown one node [say tiger] by using shut down command as
> root, the resources are moving to the other node [say dragon], which
> is good.
> Now I power back on the node which was shut down earlier that is
> tiger node.
> In pcs status I can see that the node tiger is offline.
> How to bring it online?

Hi Harishkumar,

You will get better answers from the users at clusterlabs.org mailing list
for this type of question. This list is for discussing software
development of ClusterLabs projects.

I will try to answer though:

> If I try by “pcs cluster start” on node tiger, it is getting online 

Correct. You can either enable Pacemaker to start at system boot
(systemctl enable pacemaker), or leave it so that you have to manually
start it after a reboot.

It's a matter of personal preference, whether you lean more to
automatic recovery, or investigating what happened before returning a
node back to the cluster.

> no issues there, but there is a restart of db2 in dragon node. Why
> this is happening?

Without seeing the configuration, it's hard to say. It sounds like you
want a positive resource-stickiness, though, so it would be worth
setting that in resource defaults if you haven't already.

(Any follow-ups should go to the users list.)

> My expectation is if a node goes down and the resource is moved to
> other node, after that original nodes comes back, I do not want
> pacemaker to restart things or resources on existing node that is
> dragon in my case.
> How will I configure this?
>  
> Any help will be of great significance to me. I am creating lot of
> db2 educational contents. Precisely this will be helpful for my next
> video.
> Please let me know any further information required from my side.
>  
> Thanks,
> Harish P
> YouTube.com/db2luwacademy
>  
> Sent from Mail for Windows 10
-- 
Ken Gaillot <kgaillot at redhat.com>



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