BOINC cache management


log in

Advanced search

Questions and Answers : Wish list : BOINC cache management

Author Message
Profile greencreeper
Send message
Joined: 22 Jun 03
Posts: 49
Credit: 375,997
RAC: 558
United Kingdom
Message 5499 - Posted: 9 Jul 2004, 1:35:08 UTC

I'm a member of the SETI and Predictor projects. If I set, for example, the following cache parameters in my account pages:

Predictor - LWM: 0.5, HWM: 1
SETI - LWM: 3, HWM: 5

These settings are effectively ignored by BOINC. When it communicates with the SETI scheduler and the project is down, BOINC requests more work from Predictor instead. So instead of having upto a days worth of Predictor WUs and 5 days of SETI WUs, I actually have more than 5 days of Predictor WUs. Some won't be returned before their deadline. I know what BOINC is doing - it's ensuring the cache is full according to the greatest LWM - but this isn't right. A project that is frequently down, like SETI is at the moment, will be starved of processing time because BOINC is grabbing WUs from other projects that aren't down. It's pot luck whether the LWM will be hit when a project is up - everytime my BOINC has requested WUs from SETI the project has been down. BOINC hasn't processed a SETI WU in what must be nearly a week!


j

Profile Ranz
Volunteer tester
Send message
Joined: 19 May 02
Posts: 34
Credit: 338,178
RAC: 0
United States
Message 5540 - Posted: 9 Jul 2004, 3:44:40 UTC

You can't set different LWM for different projects. When you go to the General Preferences and set your desired # of days work between xx-yy days, that preference is used for all projects, not just that one you set it on. In your example, you have the following settings:

Predictor - LWM: 0.5, HWM: 1
SETI - LWM: 3, HWM: 5


When you manually 'Update' or the next time your BOINC program contacts the server to get your preferences, it will use the 'General Preferences' of the most recent change. If, for example, you had done changes to your SETI project last, then those settings will be used. At this point, your BOINC cache should request more work to have minimum 3 days worth up to 5 days max worth of total WU's combined from both projects. Here's the note on the 'General Preferences' page:

General preferences

These apply to all BOINC projects in which you participate.
On computers attached to multiple projects, the most recently modified preferences will be used.



Ranz


Profile greencreeper
Send message
Joined: 22 Jun 03
Posts: 49
Credit: 375,997
RAC: 558
United Kingdom
Message 5826 - Posted: 9 Jul 2004, 22:18:09 UTC - in response to Message 5540.

> You can't set different LWM for different projects. When you go to the
> General Preferences and set your desired # of days work between xx-yy days,
> that preference is used for all projects, not just that one you set it on. In
> your example, you have the following settings:
>
> Predictor - LWM: 0.5, HWM: 1
> SETI - LWM: 3, HWM: 5
>
>
> When you manually 'Update' or the next time your BOINC program contacts the
> server to get your preferences, it will use the 'General Preferences' of the
> most recent change. If, for example, you had done changes to your SETI
> project last, then those settings will be used. At this point, your BOINC
> cache should request more work to have minimum 3 days worth up to 5 days max
> worth of total WU's combined from both projects. Here's the note on the
> 'General Preferences' page:
>
> General preferences
>
> These apply to all BOINC projects in which you participate.
> On computers attached to multiple projects, the most recently modified
> preferences will be used.
>

Yeah - just discovered that this morning. So that's another problem then :) Porjects are dependant on other projects - I didn't think BOINC was designed like this?? It doesn't change my original point though. If a project is frequently down, say because it's an alpha, then it's just not going to get processing time. I've had to reset Predictor to give SETI a chance.

At the moment if BOINC can't get work it immediately downloads work from the next project. It would be better if it waited a while - say another 4 attempts - before moving to the next project.


j

Heffed
Volunteer tester
Send message
Joined: 19 Mar 02
Posts: 1856
Credit: 40,736
RAC: 0
United States
Message 5854 - Posted: 9 Jul 2004, 23:29:53 UTC - in response to Message 5826.

> Yeah - just discovered that this morning. So that's another problem then :)
> Porjects are dependant on other projects - I didn't think BOINC was designed
> like this??

This is where "resource share" comes in.

> It doesn't change my original point though. If a project is
> frequently down, say because it's an alpha, then it's just not going to get
> processing time. I've had to reset Predictor to give SETI a chance.

You are correct. If a project is frequently down, it's not going to get any processing time. That would seem blatently obvious... ;-)

> At the moment if BOINC can't get work it immediately downloads work from the
> next project. It would be better if it waited a while - say another 4 attempts
> - before moving to the next project.

But why? This would only delay processing in extreme instances. (say your queue is empty, so BOINC is sitting idle)

<a> [/url]

Profile greencreeper
Send message
Joined: 22 Jun 03
Posts: 49
Credit: 375,997
RAC: 558
United Kingdom
Message 5905 - Posted: 10 Jul 2004, 1:43:15 UTC - in response to Message 5854.

> > It doesn't change my original point though. If a project is
> > frequently down, say because it's an alpha, then it's just not going to
> get
> > processing time. I've had to reset Predictor to give SETI a chance.
>
> You are correct. If a project is frequently down, it's not going to get any
> processing time. That would seem blatently obvious... ;-)
>

How is it obvious? If I'd done nothing with BOINC, then it would be happily downloading and working on Predictor WUs. It's unlikely BOINC would have processed a SETI WU until the project is more stable - and how long will it be before that's the case? A down project can still get processing time - the project doesn't have to be up for BOINC to process the project's WUs.

> > At the moment if BOINC can't get work it immediately downloads work from
> the
> > next project. It would be better if it waited a while - say another 4
> attempts
> > - before moving to the next project.
>
> But why? This would only delay processing in extreme instances. (say your
> queue is empty, so BOINC is sitting idle)
>

All I am saying is that the way it works at the moment means that Alpha, and perhaps even Beta projects, aren't likely to stand much chance against projects that are always running and always have work. If alpha projects don't get processing time they're unlikely to progress beyond alpha.

Let's say that the LWM is 3 days - that means that when the water mark is hit there are 2.99 days of work remaining. A project isn't likely to be down or workless for that long - not even SETI ;) And the example I gave of "four tries and then move on to the next project" would take place over the course of a day anyway. It's unlikely that BOINC would run out of work, and it could always have a 1 WU critical water mark - an empty queue means download work from any responding project.

j

Profile Keck_Komputers
Volunteer tester
Avatar
Send message
Joined: 4 Jul 99
Posts: 1575
Credit: 1,683,390
RAC: 571
United States
Message 5932 - Posted: 10 Jul 2004, 3:37:05 UTC

The smaller the range between high and low water marks the less amount of work you will get per connection and therefore the more likely you are to catch a specific project up.

John Keck
BOINCing since 2002/12/08

Heffed
Volunteer tester
Send message
Joined: 19 Mar 02
Posts: 1856
Credit: 40,736
RAC: 0
United States
Message 5935 - Posted: 10 Jul 2004, 4:01:16 UTC - in response to Message 5905.

> How is it obvious? If I'd done nothing with BOINC, then it would be happily
> downloading and working on Predictor WUs. It's unlikely BOINC would have
> processed a SETI WU until the project is more stable - and how long will it be
> before that's the case? A down project can still get processing time - the
> project doesn't have to be up for BOINC to process the project's WUs.

Sorry, bit of a joke there... If a project it down, it can't give you work. Therefore it cannot get any processing time. ;-)

Please excuse the levity.

<a> [/url]

John McLeod VII
Volunteer developer
Volunteer tester
Avatar
Send message
Joined: 15 Jul 99
Posts: 24064
Credit: 516,970
RAC: 133
United States
Message 6368 - Posted: 11 Jul 2004, 4:40:09 UTC

BOINC has only one queue. It has one setting for high and low marks. The most recent of these will migrate from project to host to project until all are the same for that email address.

To control how much work is done by each project use the resource share.

Questions and Answers : Wish list : BOINC cache management

Copyright © 2014 University of California