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

[Ken Gaillot]

On 05/10/2017 12:20 AM, Kristoffer Grönlund wrote:
> "Lentes, Bernd" <bernd.lentes at helmholtz-muenchen.de> writes:
> 
>> ----- On May 8, 2017, at 9:20 PM, Bernd Lentes bernd.lentes at helmholtz-muenchen.de 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.
>>> ...
>>>
>>> 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 :-))?
>>>
>>>
>>
>> crm ra info stonith:external/ipmi says there exists a parameter pcmk_delay_max.
>> Having a look in  /usr/lib64/stonith/plugins/external/ipmi i don't find anything about delay.
>> Also "crm_resource --show-metadata=stonith:external/ipmi" does not say anything about a delay.
>>
>> Is this "pcmk_delay_max" not implemented ? From where does "crm ra info stonith:external/ipmi" get this info ?
>>
> 
> pcmk_delay_max is implemented by Pacemaker. crmsh gets the information
> about available parameters by querying stonithd directly.
> 
> Cheers,
> Kristoffer

The various pcmk_* parameters are documented in the stonithd(7) man page.

Some fence agents implement a delay parameter of their own, to set a
fixed delay. I believe that's what digimer uses.

>>
>> Bernd
>>  
>>
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