[ClusterLabs] Antw: Re: Antw: Re: Antw: Struggling to get "crm_mon -E ... " to do anything

[Andrew Beekhof]

> On 12 May 2015, at 3:59 pm, Ulrich Windl <Ulrich.Windl at rz.uni-regensburg.de> wrote:
> 
> Hi!
> 
> What I don't like with all of this is that it's still a polling interface.

crm_mon isn’t doing polling, it subscribes to the cib's update channel

> That is, some program (crm_mon) has to find out what the changes are. You can get the same thing by periodically getting the CIB, watching for changes.
> What the interface should be is truely event driven; that is if the cluster is going to do something, some notifier should be executed.
> With the polling interface you are always behind the facts...
> 
> Regards,
> Ulrich
> 
>>>> Brett Moser <brett.moser at gmail.com> schrieb am 11.05.2015 um 19:29 in Nachricht
> <CAO3aD9MB9AXSUTUiURze5_i3b=x=KssuUc=oqMqXyw-ZmLvO+w at mail.gmail.com>:
>> Hi Ulrich,
>> 
>> The ClusterMon OCF must be configured with the extra_options parameter:
>> 
>> # Sample configuration
>> # ================================
>> # primitive ClusterMon ocf:pacemaker:ClusterMon \
>> #        params user="root" update="30" extra_options="-E
>> /path/to/pcmk_snmp_helper.sh -e 192.168.1.2" \
>> #        op monitor on-fail="restart" interval="10"
>> 
>> 
>> Have you looked at the pcmk_snmp_helper.sh
>> <https://github.com/ClusterLabs/pacemaker/blob/master/extra/pcmk_snmp_helper.
>> sh>
>> script that Florian CROUZAT created?   It provides a good example of how
>> to get the information provided when an external program is executed by
>> crm_mon.  The parameters are passed as Environment variables, similar to
>> how Resource Agents work in Pacemaker:
>> 
>> CRM_notify_recipient
>> CRM_notify_node
>> CRM_notify_rsc
>> CRM_notify_task
>> CRM_notify_desc
>> CRM_notify_status
>> CRM_notify_rc
>> CRM_notify_target_rc
>> 
>> regards,
>> -Brett Moser
>> 
>> 
>> On Mon, May 11, 2015 at 6:46 AM, Ulrich Windl <
>> Ulrich.Windl at rz.uni-regensburg.de> wrote:
>> 
>>>>>> Riley <riley at on.net.nz> schrieb am 11.05.2015 um 12:05 in Nachricht
>>> <55507ECD.7050706 at on.net.nz>:
>>>> Ulrich,
>>>>           well I guess 'man crm_mon' does not tell you very much, but
>>>> the ClusterMon resource uses crm_mon, and chapter 7 of the Pacemaker
>>>> documentation,
>>>> 
>>> 
>> http://clusterlabs.org/doc/en-US/Pacemaker/1.1-crmsh/html/Pacemaker_Explained 
>> /
>>>> s-notification-external.html,
>>>> documents the CRM_notify_* environment variables.
>>> 
>>> Actually I'm more confused than before now ;-)
>>> 
>>> So there is a ClusterMon OCF RA that is started by the cluster, and that
>>> monitor starts "crm_mon" to periodically dump the configuration to a HTML
>>> file. If all I can get is a text dump of the configuration, it's rather
>>> ridiculous.
>>> 
>>> I fail to see the connection to the argument to option "-E" in the
>>> documentation you are referring to, and section 7.3 (The example) really
>>> lacks an example how such variables look like (and what to do with them).
>>> 
>>> Regards,
>>> Ulrich
>>> 
>>>> 
>>>> (No arguments/parameters are passed to the program that is called via
>>>> it's command line, everything is through the environment variables)
>>>>> ...
>>>>>> I have set up a virtual test environment of three nodes running CentOS
>>>>>> 6.6 and am having trouble getting a "crm_mon -E " script called *at
>>> all*
>>>>>> when anything changes in the cluster (resource killed, node killed,
>>>>>> resource moved, etc.).
>>>>> Never heard of that option, but when considering the documentation, I'm
>>> not
>>>> much surprised if it doesn't work as one might expect:
>>>>>       -E, --external-agent=value
>>>>>              A program to run when resource operations take place.
>>>>> 
>>>>> This leaves a LOT of room for expectations. ;-)
>>>>> 
>>>>> What should be a typical use case? Will the program have any parameters?
>>>>> 
>>>> 
>>>> 
>>>> _______________________________________________
>>>> Users mailing list: Users at clusterlabs.org 
>>>> http://clusterlabs.org/mailman/listinfo/users 
>>>> 
>>>> Project Home: http://www.clusterlabs.org 
>>>> Getting started: http://www.clusterlabs.org/doc/Cluster_from_Scratch.pdf 
>>>> Bugs: http://bugs.clusterlabs.org 
>>> 
>>> 
>>> 
>>> 
>>> 
>>> _______________________________________________
>>> Users mailing list: Users at clusterlabs.org 
>>> http://clusterlabs.org/mailman/listinfo/users 
>>> 
>>> Project Home: http://www.clusterlabs.org 
>>> Getting started: http://www.clusterlabs.org/doc/Cluster_from_Scratch.pdf 
>>> Bugs: http://bugs.clusterlabs.org 
>>> 
> 
> 
> 
> 
> _______________________________________________
> Users mailing list: Users at clusterlabs.org
> http://clusterlabs.org/mailman/listinfo/users
> 
> Project Home: http://www.clusterlabs.org
> Getting started: http://www.clusterlabs.org/doc/Cluster_from_Scratch.pdf
> Bugs: http://bugs.clusterlabs.org