[ClusterLabs] how to set a dedicated fence delay for a stonith agent ?

[Klaus Wenninger]

On 05/08/2017 09:20 PM, Lentes, Bernd wrote:
> Hi,
>
> i remember that digimer often campaigns for a fence delay in a 2-node  cluster.
> E.g. here: http://oss.clusterlabs.org/pipermail/pacemaker/2013-July/019228.html
> In my eyes it makes sense, so i try to establish that. I have two HP servers, each with an ILO card.
> I have to use the stonith:external/ipmi agent, the stonith:external/riloe refused to work.
>
> But i don't have a delay parameter there.
> crm ra info stonith:external/ipmi:
>
> ...
> pcmk_delay_max (time, [0s]): Enable random delay for stonith actions and specify the maximum of random delay
>     This prevents double fencing when using slow devices such as sbd.
>     Use this to enable random delay for stonith actions and specify the maximum of random delay.
> ...
 
Sorry for resurrecting this but
https://github.com/ClusterLabs/pacemaker/commit/3e3cf385e0c9780fc95a4491703413b3dad54eb3
might be of interest.

  pcmk_delay_max: Enable random delay for stonith actions and specify
the maximum of random delay
                  This prevents double fencing when using slow devices
such as
                  sbd. Use this to enable random delay for stonith actions.
                  The overall delay is derived from a random delay value
adding a static delay so that
                  the sum is kept below the maximum delay.
  pcmk_delay_base: Enable base delay for stonith actions and specify
base delay value
                   This prevents double fencing when different delays
are configured on the
                   nodes. Use this to enable static delay for stonith
actions.
                   The overall delay is derived from a random delay
value adding a static delay so
                   that the sum is kept below the maximum delay.

Regards,
Klaus

>
> This is the only delay parameter i can use. But a random delay does not seem to be a reliable solution.
>
> The stonith:ipmilan agent also provides just a random delay. Same with the riloe agent.
>
> How did anyone solve this problem ?
>
> Or do i have to edit the RA (I will get practice in that :-))?
>
>
> Bernd
>
>