Waiting for the data transfer is exactly the problem which leads to low
cpu usage. This is a problem for sites since cpu is used in the
accounting, not wallclock. The accounting determines how much money
sites get.
Greig
Davies, BGE (Brian) wrote, On 24/11/08 11:44:
> Has anyone actually informed the user/VO that his jobs are causing
> problems. The low efficiency is probably being caused by the fact that
> while the job is waiting for input files it is idle. Ignoring the file
> transfer issue, since biomed are also a smaller VO, and therefore there
> jobs basically run when our Main V0s are not (they have low fairshare)
> does it matter if their jobs have low efficiency?
> Brian
>
> -----Original Message-----
> From: Testbed Support for GridPP member institutes
> [mailto:[log in to unmask]] On Behalf Of Alex Martin
> Sent: 24 November 2008 11:04
> To: [log in to unmask]
> Subject: Re: Biomed data transfer volumes & usage issue
>
> I should add that this same user has submitted ~11K jobs to our HTC in
> the last 2 weeks with a cpu/wall clock efficiency
> of ~ 4.6K hours/ 146K hours =~ 3% :
>
> Username njob % wall user system cpu
> biomed032 7288 20 90949 1466 224 2907
>
> biomed032 2741 16 56169 1310 100 1751
>
> cheers,
> Alex
>
> On Monday 24 November 2008, Alex Martin wrote:
>
>> A biomed user managed to start ~1000 gridftp processes on our
>> old SE node here last week.
>>
>> cheers,
>> Alex
>>
>> On Monday 24 November 2008, Coles, J (Jeremy) wrote:
>>
>>> Dear All
>>>
>>>
>>>
>>> In the site reports for last week Durham report:
>>>
>>>
>>>
>>> "A biomed user has been transferring huge amounts of data from our
>>> SE (>500
>>>
>>> requests of the same 2.8GB file to a variety of worker nodes across
>>> Europe. Unfortunately the high bandwidth has revealed instabilities
>>>
>
>
>>> when transferring at close to the gigabit limit. I ticketed the
>>> user and they have distributed more replicas - but they are not
>>> following the grid data-to-cpu model and therefore will cause severe
>>>
>
>
>>> bandwidth issues to all sites."
>>>
>>>
>>>
>>> Has any other site seen such a seeding exercise taking place or
>>> anything related?
>>>
>>>
>>>
>>> Thanks,
>>>
>>> Jeremy
>>>
>
>
>
> --
> ------------------------------------------------------------------------
> ------
> |
> |
> | Dr. Alex Martin
> |
> | e-Mail: [log in to unmask] Queen Mary, University of
> London, |
> | Phone : +44-(0)20-7882-5033 Mile End Road,
> |
> | Fax : +44-(0)20-8981-9465 London, UK E1 4NS
> |
> |
>
> | |
> ------------------------------------------------------------------------
> ------
>
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