Message boards : ATLAS application : 2-core ATLAS tasks running with 1 core only
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Erich56

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Message 32554 - Posted: 28 Sep 2017, 19:46:10 UTC

since this morning, I've observed that all 2-core ATLAS tasks are running with one CPU-core only.

This becomes evident when looking at the Windows Task Manager as well as at the console where only 1 athena.py is shown.
Also, the credit points for these tasks are about half compared to what they would normally be.

Any idea what the problem is and how it can be solved?
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Profile HerveUAE
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Message 32555 - Posted: 28 Sep 2017, 20:21:14 UTC - in response to Message 32554.  

Indeed I also have some 2-core tasks with 1 CPU core running, but only some of the tasks, not all.
We are the product of random evolution.
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Tom*

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Message 32556 - Posted: 28 Sep 2017, 21:17:23 UTC - in response to Message 32554.  
Last modified: 28 Sep 2017, 21:21:37 UTC

all your ATLAS tasks today seem to have almost twice the CPU time versus runtime
That would be normal for two cpu's running on short jobs its not quite 2x
I think the startup times which can run to 10 minutes is only done with one CPU
and with that a significant part of these short tasks might make it look like its only using one cpu

since all the tasks are short except for a few the credits will be smaller than normal. after running a lot of long jobs and having credits normalized downward short jobs get shorted on credits.

Its called creditscrew over at SETI
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tullio

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Message 32558 - Posted: 29 Sep 2017, 5:46:36 UTC

On the Windows 10 PC I had a task running on one core which gave me 3200 credits.
Tullio
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Erich56

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Message 32559 - Posted: 29 Sep 2017, 7:15:50 UTC - in response to Message 32558.  

On the Windows 10 PC I had a task running on one core which gave me 3200 credits.
Tullio

this somehow confirms that as far as credits are concerned, it's like playing lottery :-)
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David Cameron
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Message 32562 - Posted: 29 Sep 2017, 11:29:12 UTC

Can those of you experiencing the problem give links to example results? I don't see the problem myself but I'm running only native tasks at the moment.
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Message 32571 - Posted: 30 Sep 2017, 16:08:30 UTC - in response to Message 32562.  

Hi David,
The issue mentioned by Erich, and that I experienced myself as well, was apparently related to a batch of short tasks. This batch is over now I think.
I suggest to create a discussion thread dedicated to issues related to the number of athena.py processes within a task.
In this thread could be addressed both cases like this one reported by Erich, and the case I reported of duplicated and triplicated processes.
Regards,
Herve
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Erich56

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Message 32572 - Posted: 30 Sep 2017, 16:26:11 UTC - in response to Message 32562.  

David wrote:
Can those of you experiencing the problem give links to example results? I don't see the problem myself but I'm running only native tasks at the moment.

David, sorry for the late reply; this was one of them:

https://lhcathome.cern.ch/lhcathome/result.php?resultid=158264982
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Message boards : ATLAS application : 2-core ATLAS tasks running with 1 core only


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