openstack team mailing list archive

[Loic Dachary <loic@xxxxxxxxxxxx>]

On 05/01/2012 06:13 PM, Mark McLoughlin wrote:
> Hi Loic,
>
> On Mon, 2012-04-30 at 12:15 +0200, Loic Dachary wrote:
>
>> To prepare for the next meeting ( thursday 3rd, may 2012
>> http://wiki.openstack.org/Meetings/MeteringAgenda ) I cleaned up and
>> reorganized the Metering blueprint so that it ( hopefully )
>> incorporates all the information temporarily stored in the etherpad
>> ( http://etherpad.openstack.org/EfficientMetering revision 67 in case
>> it is vandalized ).
> I'm a bit late to the discussion, but some brief comments after reading
> up on what you guys have done so far:
>
>   - big +1 on separating billing from metering; there's no need to 
>     conflate the two problems and doing it this way will allow for a 
>     bunch of different ideas to be tried around billing
>
>   - I'd prefer to avoid adding a new node agents, so +1 on building on
>     the notifications system
I would also prefer this option. I have a few concerns though:

a) adding too many messages to the existing message queues
b) not all core components provide notifications
c) convincing all components to agree on a unified approach to metering

Instead it might be more practical to implement node agents when necessary to complete a first implementation. That is, taking advice from core component developers and possibly run into problems as opposed to convincing core component developers to adopt an approach to metering that is not yet implemented anywhere.
>
>   - I agree that we don't want to go too far with aggregation and lose 
>     useful data like which instances have been running as opposed to 
>     just how many instance minutes a given tenant has consumed
>
>     Another aspect of aggregation to think about is aggregation over 
>     time - e.g. I might like to see my hourly network usage has varied 
>     over the last week, or how my daily usage has varied over the last 
>     month, but I probably don't care so much about my hourly usage on a 
>     specific day 3 months ago
>
>     oVirt's equivalent of a metering service does this kind of 
>     aggregation as follows:
>
>       http://www.ovirt.org/wiki/Ovirt_DWH
>
>         * Sample data is collected at the end of every minute and is
>           kept for up to 48 hours.
>         * Hourly level is aggregated every hour for the hour before 
>           last and is kept for 2 months.
>         * Daily level is aggregated every day for the day before last
>           and is kept for 5 years. 
Where can I read a description of the corresponding database ?
>
>   - Lastly, bikeshed mode - since we're calling this "metering" and not 
>     "counting", how about just using the term "meters" rather than 
>     "counters"?
>
+1 ;-)

Cheers

-- 
Loïc Dachary         Chief Research Officer
// eNovance labs   http://labs.enovance.com
// ✉ loic@xxxxxxxxxxxx  ☎ +33 1 49 70 99 82