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Jake Bauer
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Message 61832 - Posted: 3 Jun 2014, 14:52:35 UTC

I have posted:

de_nbody_06_03_orphan_sim_0
de_nbody_06_03_orphan_sim_1
de_nbody_06_03_orphan_sim_2
de_nbody_06_03_orphan_sim_3

ps_nbody_06_03_orphan_sim_0
ps_nbody_06_03_orphan_sim_1
ps_nbody_06_03_orphan_sim_2
ps_nbody_06_03_orphan_sim_3

Please alert me to any problems.

Best wishes and good crunching,

Jake Bauer

dlk
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Message 61852 - Posted: 8 Jun 2014, 15:51:46 UTC
Last modified: 8 Jun 2014, 15:52:07 UTC

When running these, should they be using all 8 CPU's? This keeps all other projects from running.

captainjack
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Message 61853 - Posted: 8 Jun 2014, 21:45:16 UTC

Hi dlk,

Yes, there are some N-Body tasks that are multi-thread meaning they will use all of the threads that are available. In BOINC Manager, the application name is "Milkyway@Home N-Body Simulation 1.40 (mt)". If you want to restrict the number of threads they use, here is a post by Jacob Klein on using an app_config.xml to control the number of CPU's that an n-body will use. It is what I use.

http://milkyway.cs.rpi.edu/milkyway/forum_thread.php?id=3359&postid=60956

Hope that helps.

Profile Stephen Uitti
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Message 61858 - Posted: 9 Jun 2014, 22:07:14 UTC

I have an N-Body 1.40 (mt) running on my laptop (id 563836), task id 758776399 (or 758776398), The laptop has two AMD cores. It's been running for 123 hours, and has about 8 hours left (it's at 93.998%). So, that's 5.5 days, total. I thought it might be stuck at first, but it makes percent progress. The CPU estimate was grossly low, and is low by an hour even still. It's due date is 6/15. I have another in the queue, not yet started, also due 6/15. It's not a sure thing that it could finish by the deadline.

I expect really poor credit from this, as the estimate was so dreadfully wrong. But we'll see.

I also have no idea why it shouldn't take more like twice the wall clock or so of my 4 core desktops.

I've heard in other forums of bad estimates due to BOINC using a CPU benchmark for an essentially FPU intensive app, or the other way around. Obviously, the best benchmark would be one where after a half hour or so, the current unit's progress would be used for the estimate. And, previous units of the exact same type would be used over BOINC's guess. I have no idea if this is in the control of Milky Way or BOINC, however.

I've allowed a 4 core desktop to do some units. Usually, Milky Way prevents my GPU from running. But Collatz is currently down, and some have finished. For example, 2,706.26 CPU seconds finishes in 739.62 seconds, which is like 12 minutes. but i get 27 credit, which is about a quarter of what i get for similar CPU time units. Perhaps the credit is based on wall clock instead of CPU time.

Profile Stephen Uitti
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Message 61859 - Posted: 9 Jun 2014, 22:12:03 UTC - in response to Message 61858.

One difference, the laptop running for days is Windows, the 4 core desktop is Linux.

Eric Findley
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Message 61902 - Posted: 15 Jun 2014, 21:44:04 UTC

I have had 3 N body simulations error out on me today am I doing something wrong??
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Message 61903 - Posted: 16 Jun 2014, 16:35:43 UTC - in response to Message 61902.
Last modified: 16 Jun 2014, 16:36:24 UTC

Nearly all of the xx_nbody_06_10_orphan_sim_x runs I've had recently have ended up with errors so no, it's probably not you :)

Eric Findley
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Message 61910 - Posted: 17 Jun 2014, 22:41:55 UTC

seems like a waste of everybody's time to run them then, Ya think?
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Richard Haselgrove
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Message 61911 - Posted: 17 Jun 2014, 23:13:17 UTC - in response to Message 61910.

seems like a waste of everybody's time to run them then, Ya think?

Why not try posting the actual cause of the error for Jake to see and do something about?

Exit status 196 (0xc4) EXIT_DISK_LIMIT_EXCEEDED

The task is trying to use more disk space than is allowed for by the <rsc_disk_bound> value in the workunit template. They can fix that...

Konstantin_SnZ
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Message 61912 - Posted: 18 Jun 2014, 15:21:40 UTC
Last modified: 18 Jun 2014, 16:03:39 UTC

I`ve got 2 runs of these tasks each lasting for about 30hours on phenom II x4 3.2ghz(with 85% load), while predicted runningtime was 10 times smaller, is it ok? [It`s the biggest runtime i`ve got here ever.]

Eric Findley
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Message 61935 - Posted: 22 Jun 2014, 19:29:11 UTC - in response to Message 61911.

seems like a waste of everybody's time to run them then, Ya think?

Why not try posting the actual cause of the error for Jake to see and do something about?

Exit status 196 (0xc4) EXIT_DISK_LIMIT_EXCEEDED

The task is trying to use more disk space than is allowed for by the <rsc_disk_bound> value in the workunit template. They can fix that...

my latest error-Name ps_nbody_06_10_orphan_sim_1_1398336302_1400532_0
Workunit 576435525
Created 18 Jun 2014, 23:09:09 UTC
Sent 18 Jun 2014, 23:43:14 UTC
Received 21 Jun 2014, 16:07:10 UTC
Server state Over
Outcome Computation error
Client state Compute error
Exit status 196 (0xc4) EXIT_DISK_LIMIT_EXCEEDED
Computer ID 554457
Report deadline 30 Jun 2014, 23:43:14 UTC
Run time 129,784.20
CPU time 775,689.20
Validate state Invalid
Credit 0.00
Application version MilkyWay@Home N-Body Simulation v1.40 (mt)

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Jeffery M. Thompson
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Message 61945 - Posted: 25 Jun 2014, 2:32:29 UTC
Last modified: 25 Jun 2014, 2:50:59 UTC

We are trying to see what is up with the runs.
The Jakes and Roland are looking at the code.
The error rates seem to be spiking and it may be the parameters it are in.


I don't have details to post now will post more to follow as I get some more tests in....

UPDATE: Jake Bauer has a fix in works and we are working to get that tested and out.


Jeff Thompson

Jake Bauer
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Message 61946 - Posted: 25 Jun 2014, 16:17:30 UTC

I have fixed the underlying issue. It was necessary that these runs be up for this period of time for the science. This issue will not occur in the future. Expect to stop getting problematic workunits in the next week.

Apologies,

Jake

Jake Bauer
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Message 61947 - Posted: 25 Jun 2014, 16:23:30 UTC - in response to Message 61858.

The workunits take vastly different amounts of time to complete. This is a problem that we at MW@Home have been working on to assign appropriate credit to crunchers. Our goal is to ultimately perfect this art and prevent the assignment of non-useful simulations that are time-expensive. You are right to say that for the same simulation, the wall clock time on your 4 core machine should be half that of your dual AMD cores. I can go into more detail. If you send me a private message, I would be glad to explain the science of how the workunits are very difficult to assess computationally. I hope that I can answer any questions you may have.

Jake

Richard Haselgrove
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Message 61948 - Posted: 25 Jun 2014, 16:49:11 UTC - in response to Message 61947.

The workunits take vastly different amounts of time to complete. This is a problem that we at MW@Home have been working on to assign appropriate credit to crunchers. Our goal is to ultimately perfect this art and prevent the assignment of non-useful simulations that are time-expensive. You are right to say that for the same simulation, the wall clock time on your 4 core machine should be half that of your dual AMD cores. I can go into more detail. If you send me a private message, I would be glad to explain the science of how the workunits are very difficult to assess computationally. I hope that I can answer any questions you may have.

Jake

Have you talked with David Anderson about CreditNew's crediting of MT tasks? I mean *really* talked to him, challenging his position with facts, rather than just receiving the standard speech that it works?

YAFU (YoYo's Beta project) are having the same problem: http://boinc.berkeley.edu/dev/forum_thread.php?id=9317

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Message 62449 - Posted: 1 Oct 2014, 13:31:36 UTC

I have preferences set to not run N-Body's, but they still run, using all CPU's & threads.

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Message 62450 - Posted: 1 Oct 2014, 13:57:00 UTC

dlk,

Did you also uncheck the box for the option "If no work for selected applications is available, accept work from other applications"?

dlk
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Message 62460 - Posted: 3 Oct 2014, 13:36:41 UTC - in response to Message 62450.
Last modified: 3 Oct 2014, 13:38:41 UTC

captainjack,

Thanks. Would never have considered that. Silly me, thought "no" meant "no". Might consider another machine for just N-Body (mt) runs.


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