[ofa-general] IB performance stats (revisited)

Hal Rosenstock halr at voltaire.com
Wed Jul 11 06:31:14 PDT 2007


Hi Eitan,

On Wed, 2007-07-11 at 06:51, Eitan Zahavi wrote:
> Hi Ira,
> 
> > Second, I have run some tests querying the fabric of our 
> > large clusters here (~500 nodes) and the results were 
> > promising for a single node implementation.
> > I don't recall the numbers as this was a while ago but it was 
> > on the order of
> > <2 sec and I think <1 but I don't want to be misquoted.
> 
> Does PerfMgr query switch ports ?

Yes (of course it does).

> If it does I am surprised by the short sweep time you got.
> 
> Does it have >1 query on the wire at a given time?

Yes, Default appears to be 500 currently (maybe that needs dialing back
a bit) but is settable via perfmgr_max_outstanding_queries in options
file.

> If not then I am even more surprised.
> 
> Was the cluster running a job at the time of the query ?

Is this question related to VL0 contention ?

-- Hal

> Thanks
> 
> Eitan Zahavi
> Senior Engineering Director, Software Architect
> Mellanox Technologies LTD
> Tel:+972-4-9097208
> Fax:+972-4-9593245
> P.O. Box 586 Yokneam 20692 ISRAEL
> 
>  
> 
> > -----Original Message-----
> > From: Ira Weiny [mailto:weiny2 at llnl.gov] 
> > Sent: Tuesday, July 10, 2007 7:47 PM
> > To: Eitan Zahavi
> > Cc: halr at voltaire.com; Mark.Seger at hp.com; 
> > general at lists.openfabrics.org; Ed.Finn at FMR.COM
> > Subject: Re: [ofa-general] IB performance stats (revisited)
> > 
> > On Thu, 28 Jun 2007 10:24:59 +0300
> > "Eitan Zahavi" <eitan at mellanox.co.il> wrote:
> > 
> > > > On Wed, 2007-06-27 at 14:23, Eitan Zahavi wrote:
> > > > > In the last months it is the second time I hear people
> > > > complaining the
> > > > > current monitoring solution in OFA is  integrated with OpenSM.
> > > > 
> > > > I must have missed this both times (didn't see this in Mark's
> > > > post) and the statement itself is somewhat inaccurate as well.
> > > Private talks - I hope they will speak up for themselves now...
> > > > 
> > > > > These people do not use OpenSM but do use OFED.
> > > > 
> > > > I'm not sure I'm following what you mean here.
> > > > 
> > > > If you mean that some people want to run PerfMgr without 
> > the SM/SA 
> > > > aspects (so that they can run a vendor based SM), that is 
> > the next 
> > > > thing we are adding to the implementation.
> > > Exactly. OK when is that coming?
> > 
> > There is very little which ties the current PerfMgr to 
> > OpenSM.  Basically it just gets the current fabric topology.  
> > As Hal has said changes are coming.
> > 
> > >
> > > > 
> > > > >  Another drawback if that
> > > > > no naming is provided and the reporting uses GUIDs.
> > > > 
> > > > Naming is provided via NodeDescription.
> > > This might be good for hosts but is not covering  switches ...
> > 
> > It does include switches.  However, since most systems have 
> > the same name for multiple switches this becomes ineffective. 
> >  I have queried Voltaire for a way to change the 
> > NodeDescription for switches, but at the time I asked, there 
> > was no way to do it.  Perhaps there is now?  What about other 
> > vendors?  This is why ibnetdiscover and other diags have 
> > "switch map" support.  (A GUID->name mapping to override the 
> > default NodeDescription.) Nothing would please me more than 
> > to be able to remove that for a more "automatic" solution.
> > 
> > > > 
> > > > > I also can't hold myself from saying again I think you 
> > are going 
> > > > > to hit the wall with the concept of doing the PMA from 
> > a single node.
> > > > 
> > > > If you are referring to the fact the PerMgr is currently not 
> > > > distributed, that will be done as has been stated before.
> > > Good. When is it expected? Will it be OFED 1.3?
> > 
> > When Hal first sent out the PerfMgr design I thought we 
> > should jump right to the distributed model as well.  But now 
> > I am glad we have gone the way we did.
> > First off, we have something which "works" and from which we 
> > can expand.
> > Second, I have run some tests querying the fabric of our 
> > large clusters here (~500 nodes) and the results were 
> > promising for a single node implementation.
> > I don't recall the numbers as this was a while ago but it was 
> > on the order of
> > <2 sec and I think <1 but I don't want to be misquoted.
> > 
> > For sure, a distributed model offers many advantages and we 
> > will get there.  But for many the current single node 
> > approach should work just fine.
> > 
> > Thanks,
> > Ira
> > 
> > > 
> > > Thanks
> > > > 
> > > > -- Hal
> > > > 
> > > > > Eitan Zahavi
> > > > > Senior Engineering Director, Software Architect Mellanox
> > > > Technologies
> > > > > LTD
> > > > > Tel:+972-4-9097208
> > > > > Fax:+972-4-9593245
> > > > > P.O. Box 586 Yokneam 20692 ISRAEL
> > > > > 
> > > > >  
> > > > > 
> > > > > > -----Original Message-----
> > > > > > From: general-bounces at lists.openfabrics.org
> > > > > > [mailto:general-bounces at lists.openfabrics.org] On 
> > Behalf Of Hal 
> > > > > > Rosenstock
> > > > > > Sent: Wednesday, June 27, 2007 8:12 PM
> > > > > > To: Mark Seger
> > > > > > Cc: Finn, Ed; general at lists.openfabrics.org
> > > > > > Subject: Re: [ofa-general] IB performance stats (revisited)
> > > > > > 
> > > > > > On Wed, 2007-06-27 at 13:07, Mark Seger wrote:
> > > > > > > >The performance managers deal with the counter 
> > stickiness (by 
> > > > > > > >resetting them when they think they need to). They
> > > > > > typically export
> > > > > > > >their data although this is not specified by IBA so it is
> > > > > > in a vendor
> > > > > > > >proprietary manner.
> > > > > > > >  
> > > > > > > >
> > > > > > > so I guess these guys are poor citizens as well...
> > > > > > 
> > > > > > Not sure what you mean.
> > > > > > 
> > > > > > > the real issue as I see it then means nobody can trust
> > > > the data if
> > > > > > > randon tools randomly reset the counters.  a real shame...
> > > > > > 
> > > > > > I consider this to be a real rather than random app for this. 
> > > > > > Guess it depends on what one considers random.
> > > > > > 
> > > > > > -- Hal
> > > > > > 
> > > > > > > -mark
> > > > > > > 
> > > > > > > 
> > > > > > 
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