[Pacemaker] Enable remote monitoring

[Andrew Beekhof]

On Fri, Nov 9, 2012 at 10:25 PM, Lars Marowsky-Bree <lmb at suse.com> wrote:
> On 2012-11-09T11:04:15, Andrew Beekhof <andrew at beekhof.net> wrote:
>
>> So I was just explaining the problem and context to David... his
>> comment was "aren't these just unmanaged resources and some
>> constraints?".
>
> They can even be managed - the start would be a "while ! monitor ; sleep
> 1 ; done" fake, and similar for stop. And then you could see the
> services wink in and out too.

ack

>
>> Of course its slightly more complex than that, but what if we made a
>> "container" type in the PE?
>> Something analogous to groups (ie. a parent with N children) but
>> possibly without the internal ordering.
>
> Yes. We thought about a new meta attribute to a group too.
>
>> Conceptually its also a little closer to how the admin probably thinks
>> of the system and we'd make the semantics be that you don't start
>> monitoring the children until the parent is fully up and any failures
>> are a failure of the parent (optional?).
>
> Right, the last bit is the interesting one. Basically, an ordering
> dependency which works the other way around for "monitor" than it works
> for start/stop, and that could be turned on for the group via the
> special attribute.
>
> There is one downside that I've not yet been able to circumvent:
> templates. The monitor op would have allowed one to write something
> like:
>
> rsc_template vm-web ocf:heartbeat:VirtualDomain ... \
>         op monitor nagios:http ...
>
> With the container syntax, this will look like:
>
> primitive vm-web-1 ocf:heartbeat:VirtualDomain ...
> primitive vm-web-1-monitor nagios:http ...
> group container-vm-web-1 vm-web-1 vm-web-1-monitor \
>         meta container="vm-web-1"
>
> For each VM. i.e., the CIB would blow up considerably more. But that
> might be acceptable and solved later ...?

Well you can still use templates for and within the container.
Its also possible for shells and GUIs to hide some of the
configuration and status details if they like.
You can represent it any way you like, it doesn't have to match the
XML object-for-object.

>
>
> Regards,
>     Lars
>
> PS: any UI tool could render "group ... meta container='vm-web-1'" as
> "container ..." directly, too. Just thinking this might make the XML
> neater.
>
> --
> Architect Storage/HA
> SUSE LINUX Products GmbH, GF: Jeff Hawn, Jennifer Guild, Felix Imendörffer, HRB 21284 (AG Nürnberg)
> "Experience is the name everyone gives to their mistakes." -- Oscar Wilde
>
>
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