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["Day, Phil" <philip.day@xxxxxx>]

Hi All,

I'm looking at the network bandwidth code with a view to how the current framework could be made to work with libvirt, and a I have a couple of questions that hopefully someone familiar with the Xen implementation can answer:


-          Do the Xen counters get reset after they are read, or are the values always cumulative ?   (I'm guessing the latter as they seem to be just overwritten by the periodic task).



-          It looks as if the table is intended to provide a set of values per instance_uuid/mac combination (presumably to have counters per NIC), but the code which updates the entries looks like it always just updates the first entry it finds for a particular uuid:

        bwusage = model_query(context, models.BandwidthUsage,
                              session=session, read_deleted="yes").\
                              filter_by(start_period=start_period).\
                              filter_by(uuid=uuid).\
                             first()

        if not bwusage:
            ...

Thanks,
Phil