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> On 3/25/2014 1:50 PM, Matt Wagner wrote:
> > This would argue to me that the easiest thing for Ceilometer might be
> > to query us for IPMI stats, if the credential store is pluggable.
> > "Fetch these bare metal statistics" doesn't seem too off-course for
> > Ironic to me. The alternative is that Ceilometer and Ironic would both
> > have to be configured for the same pluggable credential store.
> 
> There is already a blueprint with a proposed patch here for Ironic to do
> the querying:
> https://blueprints.launchpad.net/ironic/+spec/send-data-to-ceilometer.

Yes, so I guess there are two fundamentally different approaches that
could be taken here:

1. ironic controls the cadence of IPMI polling, emitting notifications
   at whatever frequency it decides, carrying whatever level of
   detail/formatting it deems appropriate, which are then consumed by
   ceilometer which massages these provided data into usable samples

2. ceilometer acquires the IPMI credentials either via ironic or
   directly from keystone/barbican, before calling out over IPMI at
   whatever cadence it wants and transforming these raw data into
   usable samples

IIUC approach #1 is envisaged by the ironic BP[1].

The advantage of approach #2 OTOH is that ceilometer is in the driving
seat as far as cadence is concerned, and the model is far more
consistent with how we currently acquire data from the hypervisor layer
and SNMP daemons.

Cheers,
Eoghan


[1]  https://blueprints.launchpad.net/ironic/+spec/send-data-to-ceilometer
 
> I think, for terms of credential storage (and, for that matter, metrics
> gathering as I noted in that blueprint), it's very useful to have things
> pluggable. Ironic, in particular, has many different use cases: bare
> metal private cloud, bare metal public cloud, and triple-o. I could
> easily see all three being different enough to call for different forms
> of credential storage.