Strange Boinc Manager Task Switching Behavior

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MossyRock

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Joined: 19 Oct 13
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Message 54601 - Posted: 26 Jun 2014, 12:46:19 UTC

Hello,

I'm running BM ver. 7.2.42 (x64) on a Windows 7 Pro 64-bit, 8-core AMD FX-8350 machine with 8GB of memory.

Everything was running smoothly when I was running just POGS and GPUGRID - there was no task switching occurring.

I then added climateprediction.net and World Community Grid, so now there are four projects running. All show 25% resource share.

What's happening now is POGS gets almost no compute time - the POGS tasks sit with "waiting to run" most of the time. Then, after several days, all the other projects start getting "no need" messages for new tasks, the queue dries up except for the waiting POGS tasks, and then POGS starts running. When they are done, or nearly so, the queue starts filling up again with the other projects and the cycle repeats.

The switching interval is set at the default - every 60 minutes, and I have it set to use 100% of the processors, use 100% of CPU time. Computing and GPU use is allowed while computer is in use, and applications are left in memory while suspended.

I've waited before writing this because I've read that BM eventually gets everything sorted and starts switching tasks normally again, but I'm not seeing this happening. This behavior has been going on for about a week.

Any suggestions?
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Profile Gary Charpentier
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Message 54607 - Posted: 26 Jun 2014, 15:31:45 UTC - in response to Message 54601.  

You are describing "normal" switching behavior.

The computer does not play favorites. It is next to impossible for man not to, so the pattern behind the way the computer switches seems schizophrenic to a man. Be assured there is method behind the madness.

Its first priority is to be sure that all work is completed by the deadline. Once it is happy with that it will look at the % of time for a project. When it requests more work it tries to level out the % per project, but stuff can get in the way. A project might be temporarily out of work. A project may return "long" work units. Whatever happens, it has to take it and deal with it. Over a month long time frame you should see it honoring the %'s, but never hour by hour.
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MossyRock

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Message 54616 - Posted: 27 Jun 2014, 0:38:20 UTC - in response to Message 54607.  

Gary,

Thanks for your response. I suspect that climateprediction.net with its very long WUs is what tipped the cart.

I'll go ahead and accept this as "normal" behavior and not worry about it.
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MossyRock

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Message 54627 - Posted: 28 Jun 2014, 13:56:30 UTC
Last modified: 28 Jun 2014, 14:01:26 UTC

I'll take that back - I'm starting to worry.

BM hasn't switched to POGS for three days. Eight POGS WUs (4 waiting to run, 4 ready to start) have a deadline of tomorrow, 6/29/2014 between 5:40am and 9:00am, and it still hasn't switched to them. It's now 6/28/2014 at 6:55am PST.

WCG and GPUGRID are the only other two projects running. Climateprediction.net has no tasks available. It's still downloading new WCG and GPUGRID WUs and trying to get new climateprediction.net WUs.

I'm going to let BM do its thing with no micro-managing from me to see what happens with the POGS WUs. BM is supposed to recognize this situation and finish WUs that are about to hit a deadline.
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Claggy

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Message 54628 - Posted: 28 Jun 2014, 14:08:17 UTC - in response to Message 54627.  

What are your cache settings?

Claggy
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MossyRock

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Message 54630 - Posted: 28 Jun 2014, 14:24:23 UTC - in response to Message 54628.  
Last modified: 28 Jun 2014, 14:26:22 UTC

Minimum work buffer: .10 days
Max additional work buffer: .50 days
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Claggy

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Message 54633 - Posted: 28 Jun 2014, 17:20:52 UTC - in response to Message 54630.  
Last modified: 28 Jun 2014, 17:25:11 UTC

Minimum work buffer: .10 days
Max additional work buffer: .50 days

Boinc 7 has a the ground up rewritten scheduler, the first setting is how much Boinc should cache all the time, every half a day it'll ask for work to bring the level of work up to 0.6 days,
then it'll wait for the level of work to drop below 0.1 days before asking again,

The first setting also means how much time the host is going to be off the net, So Boinc will try and get all the work done by 0.1 days before deadline,
were you to swap the setting around to 0.5 minimum, and 0.1 additional, Boinc will then try and get work done 0.5 days before deadline, (It'll bump tasks into high priority to get them done sooner, rather than doing round robin scheduling)
it'll still cache 0.6 days total, but it'll ask every 0.1 days to keep it at 0.6 days.

Claggy
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MossyRock

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Message 54649 - Posted: 30 Jun 2014, 2:59:38 UTC - in response to Message 54633.  

Thanks, Claggy, for the explanation.

BM finished all of the POGS tasks with only 9 hours to spare, much too close for comfort for me. Now it has no POGS tasks queued, saying that it doesn't need any, opting for the other three projects instead.

It's crunched extremely little POGS as compared to the others aver the past few weeks.

Whatever... I'll just let it alone for a month to see if it finally decides to start including POGS again to any material degree.
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MossyRock

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Message 54778 - Posted: 6 Jul 2014, 13:15:22 UTC

Update: It's now switching amongst all projects in a regular manner.
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Message boards : Questions and problems : Strange Boinc Manager Task Switching Behavior

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