openstack team mailing list archive

[Doug Hellmann <doug.hellmann@xxxxxxxxxxxxx>]

On Wed, Jul 25, 2012 at 10:45 AM, Aguiar, Glaucimar (Brazil R&D-ECL) <
glaucimar.aguiar@xxxxxx> wrote:

>  Doug,****
>
> ** **
>
> Thanks for sending this out. I am interested in this project and as I
> could not have it working yet with my Essex release of OpenStack
>

Some of the pieces work with Essex, but the actual daemons don't, yet. We
are planning to discuss this at our meeting this Thursday (
http://wiki.openstack.org/Meetings/MeteringAgenda).


> I would like to better understand the metrics collected you mention below.
> ****
>
> I have being reading the documentation and code extensively and would like
> to count on your help to better understand some aspects of the ceilometer.
> ****
>
> ** **
>
> Some questions below, sorry if they sound so easy for you but if you could
> help me with these, this would be of a great help for me.
>

These are good questions, thanks for bringing them up!


> ****
>
> ****
>
> When you say CPU usage meters, does it mean ceilometer is already capable
> of reporting the cpu consumption over an hour?
>

We are currently polling libvirt periodically to get the total CPU time for
an instance. The frequency of polling is adjustable, but I think the
default is 10 minutes. The value returned by libvirt represents the total
time for the instance, but a client could pull the data and perform the
calculation over a period of time. The API we have defined allows for
querying within a time range, for example.


> Does this take into account the number of CPUs of the instance or this
> should be derived from the instance data?
>

The number of CPUs in an instance is part of the metadata associated with
the counter, but does not enter into the calculation of CPU-time as far as
I know. We ask libvirt for that info, and just use what we're given.


> ****
>
> ** **
>
> Thank you very much for any help in increasing my understanding of the
> behavior of this component. I can also contact you in IRC if you prefer.
>

I hope my answers help,
Doug


> ****
>
> ** **
>
> Regards,****
>
> Glaucimar Aguiar****
>
> ** **
>
> ** **
>
> *From:* openstack-bounces+glaucimar.aguiar=hp.com@xxxxxxxxxxxxxxxxxxx[mailto:
> openstack-bounces+glaucimar.aguiar=hp.com@xxxxxxxxxxxxxxxxxxx] *On Behalf
> Of *Doug Hellmann
> *Sent:* quarta-feira, 25 de julho de 2012 11:24
> *To:* openstack-operators@xxxxxxxxxxxxxxxxxxx;
> openstack@xxxxxxxxxxxxxxxxxxx
> *Subject:* [Openstack] [ceilometer] requesting feedback on priorities for
> metering data collection****
>
> ** **
>
> When the ceilometer project started after the Folsom summit, we compiled a
> list of metrics to be collected [1]. We have reached a stage in the project
> where we are ready to start implementing more of these meters, and would
> like some input from the rest of the community about priorities. We have
> implemented the instance counter, disk I/O, and CPU usage meters, and have
> begun working on collecting some of the network statistics. If you are
> interested in using ceilometer for tracking usage in your cloud deployment,
> please let us know which other metrics you will find especially useful.***
> *
>
> ** **
>
> Thanks,****
>
> Doug****
>
> ** **
>
> 1 - http://wiki.openstack.org/EfficientMetering#Meters****
>