On 05/04/2011 14:33, Ewan MacMahon wrote:
>> -----Original Message-----
>> From: Testbed Support for GridPP member institutes [mailto:TB-
>> [log in to unmask]] On Behalf Of Stephen Jones
>>
>> Ewan MacMahon wrote:
>>> My understanding of the currently available information is that the
>>> benchmark value published in GlueHostProcessorOtherDescription should
>>> be the weighted average for the CPUs behind a CE, and should not be
>>> scaled. If my understanding is correct then I think that's the value
>>> that you're looking for.
>>
>> You're understanding is correct. The
>> GlueHostProcessorOtherDescription:benchmark
>> is the total hepspec06 of the cluster, divided by the number of logical
>> cpus in that cluster. It therefore represents the average strength of one
>> logical cpu.
>>
>> AFAIKS, this is the same value that we would have put in the lookup table.
>> Having it available from the BDII means that we don't need to provide
>> anything at all.
>>
> I've been having a read around and from various references, including this:
> https://twiki.cern.ch/twiki/bin/view/LCG/Site-info_configuration_variables
> I'm pretty sure that this value is:
> - Not the one used by APEL,
> - Not altered at sites using CPU time scaling,
> - Is either accurate, or a weighted average across the nodes behind a given queue,
> - Is the value that ATLAS are asking for.
>
> Now, if I'm right then Andrew can just pull this from the information system
> and the rest of us can stop thinking about it for now. So, anyone think I'm
> not right?
Is there a clearer definition of the "Benchmark" variable
than in the above Twiki URL?
"The second value of this attribute MUST be published only in the case
the CPU power of the SubCluster is computed using the Benchmark
HEP-SPEC06."
ie cores vs logical CPUs? ie including hyperthreads or not?
It would also need cross-referencing from the CE-queue names in the
Dashboard to the CE host+domain names in the BDII, but that should be
straightforward since (as far as I can see) the CE host names all match
in both places.
Cheers,
Andrew
--------------------------------------------------------------
Dr Andrew McNab, High Energy Physics, University of Manchester
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