[Users] oVirt 3.5 planning - bandwidth/cpu/io accounting

Doron Fediuck dfediuck at redhat.com
Fri Mar 14 04:52:47 UTC 2014



----- Original Message -----
> From: "Dan Kenigsberg" <danken at redhat.com>
> To: "Itamar Heim" <iheim at redhat.com>, ydary at redhat.com, masayag at redhat.com, nyechiel at redhat.com, msivak at redhat.com
> Cc: users at ovirt.org
> Sent: Wednesday, March 12, 2014 3:26:49 PM
> Subject: Re: [Users] oVirt 3.5 planning - bandwidth/cpu/io accounting
> 
> On Thu, Feb 27, 2014 at 12:03:55PM +0000, Dan Kenigsberg wrote:
> > There are users that would like to tell how much traffic each vnic of
> > each VM has consumed in a period of time. Currently, we report only
> > bitrate as a percetage of an estimated vnic "speed". Integrating this
> > value over time is inefficent and error prone.
> > 
> > I suggest to have all the stack (Vdsm, Engine, dwh) report the
> > actually-trasmitted (and actually-received) byte count on each vnic, as
> > well as the time when the sample was taken.
> > 
> > Currently, Vdsm reports
> > 
> >                    'eth0': {'rxDropped': '0',
> >                             'rxErrors': '0',
> >                             'rxRate': '8.0',
> >                             'speed': '1000',
> >                             'state': 'up',
> >                             'txDropped': '0',
> >                             'txErrors': '0',
> >                             'txRate': '10.0'},
> > 
> > but it should add rxKiBytes, txKiBytes and time to the frill.
> > 
> > GUI could still calculate the rate for illustration, based on the raw
> > trasmission and the sample time.
> > 
> > Until we break backward compatibility, we'd keep reporting the flaky
> > rxRate/txRate, too.
> > 
> > I can think of only two problems with this approach: Linux byte counters
> > would
> > eventually reset when they overflow. This is currently hidden by Vdsm, but
> > with
> > the suggested change, would have to be handled by higher levels of the
> > stack.
> > 
> > A similar problem appears on migration: the counters would reset and Engine
> > would need to know how to keep up the accounting properly.
> > 
> > I've opened
> > 
> >     Bug 1066570 - [RFE] Report actual rx_byte instead of a false rxRate
> > 
> > to track this request of mine.
> 
> For the reconrd, I'm told that there is a very similar need for
> reporting accumulated guest CPU cycle IO operations consuption.
> Martin, do we already have BZs for the other two use cases?
> 

No.
Please open an RFE for ovirt on these use cases.

Thanks,
Doron



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