Workunits with unreasonably high credits

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fwjmath

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Joined: 1 Feb 12
Posts: 4
Credit: 1,887,833
RAC: 0
Message 771 - Posted: 14 Jan 2013, 21:35:40 UTC

Hello everyone,

I have been crunching here for a few days. Today I happened to have a look at my result page and found quite a few strange workunits:

http://numberfields.asu.edu/NumberFields/workunit.php?wuid=1814432
http://numberfields.asu.edu/NumberFields/workunit.php?wuid=1813770
http://numberfields.asu.edu/NumberFields/workunit.php?wuid=1812336

They are so short, but granted with an improportionally great amount of credits (2,482.28 for each, less than 1 minute running time). I am feeling uneasy for earning credits without crunching. Can admins check all similar workunits and sort things straight?

I would love to know the reason of this incidence. Is there a problem on the credit system here? Could admins explain a bit how the credit system works here?

Thank you in advance for your time.

Cheers,
fwjmath.
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Profile Eric Driver
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Joined: 8 Jul 11
Posts: 945
Credit: 103,971,430
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Message 772 - Posted: 15 Jan 2013, 3:12:22 UTC - in response to Message 771.  

Hello everyone,

I have been crunching here for a few days. Today I happened to have a look at my result page and found quite a few strange workunits:

http://numberfields.asu.edu/NumberFields/workunit.php?wuid=1814432
http://numberfields.asu.edu/NumberFields/workunit.php?wuid=1813770
http://numberfields.asu.edu/NumberFields/workunit.php?wuid=1812336

They are so short, but granted with an improportionally great amount of credits (2,482.28 for each, less than 1 minute running time). I am feeling uneasy for earning credits without crunching. Can admins check all similar workunits and sort things straight?

I would love to know the reason of this incidence. Is there a problem on the credit system here? Could admins explain a bit how the credit system works here?

Thank you in advance for your time.

Cheers,
fwjmath.


It appears that all the anamolous cases have cpu_time identically 0. Furthermore, as you point out, they all have the same credit, which happens to be the maximum allowed value. I will have to look deeper into the credit granting code to see what exactly is going on there.

I made a small change to the code a few months back to curb some cheating. One of my checks may have been something like "if(cpu_time>0)..." which would obviously have problems when cpu_time=0. Just so you know, this project does not use credit new; it uses the credit from runtime method.

Thanks for reporting this!
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Profile Eric Driver
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Joined: 8 Jul 11
Posts: 945
Credit: 103,971,430
RAC: 68,572
Message 773 - Posted: 15 Jan 2013, 4:55:46 UTC - in response to Message 772.  

OK. I did find a flaw in the logic- I wasn't accounting for the case when cpu_time=0. It is now fixed. Note that this "bug" was related to one of my project specific modifications; the standard boinc server code is fine.

Good catch fwjmath! Thanks again.
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fwjmath

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Joined: 1 Feb 12
Posts: 4
Credit: 1,887,833
RAC: 0
Message 774 - Posted: 15 Jan 2013, 7:59:38 UTC - in response to Message 773.  

The fix works:
http://numberfields.asu.edu/NumberFields/workunit.php?wuid=1815921

Thanks you for the quick reply and the quick fix!
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Message boards : Number crunching : Workunits with unreasonably high credits


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