[openstack-dev] [Metering] Different polling intervals for each pollster

Domas Monkus domas.monkus at canonical.com
Fri Nov 9 08:09:02 UTC 2012


Hi,

> collector {
>   disk.io: 300,
>   instance: 60,
>   *: 600,
> }
>
> cloudwatch {
>   cputime: 300,
>  *: 0,
> }>
> would mean the ceilometor-collector publisher would require disk.io
> counters every 5 minutes, instance every minute, and the reset every 10
> minutes.

Since I am new to the ceilometer project and since a publisher is not 
mentioned in the architecture 
(http://ceilometer.readthedocs.org/en/latest/architecture.html), I want 
to make sure I understand everything clearly.

Am I right in understanding that the ceilometer-collector publisher is 
the [collector] component in the architecture diagram? Then the 
cloudwatch component must be the [central agent]. If I am correct, then 
I think there is a misunderstanding lurking somewhere here.

Since the feature to be implemented is centred around different polling 
intervals for pollsters, it is unclear to me how the collector 
component comes into play. If my reading of the ceilometer architecture 
and documentation is correct, the collector does not interact with 
pollsters directly, but listens to the information they emit (via the 
central agent) on the event bus. Does this mean that the collector 
should be able to aggregate metering information emitted by pollsters 
and publish it on the bus only at set intervals, even though the 
pollsters may be emitting it more frequently?

On a similar note, since agent plugins (e.g. plugins of the compute 
agent) are also polled at a set interval, will we need to support 
different polling intervals for these too?

And finally, as I understand, a single pollster can emit several 
measurements. Will the polling frequency be set per-pollster or 
per-pollster's-measurement? This is an important question, since the 
solution will vary depending on the decision.


Best regards,
Domas Monkus



More information about the OpenStack-dev mailing list