Too many units downloaded
5 Apr 2005 14:33:27 UTC
Topic 188875
(moderation:
With Einstein getting 30% of my 800 MH system that is on about 12 hours a day it takes almost a week to do one unit. My problem is that everytime a new one starts a second is downloaded. The second will be almost past the due date before it starts. My queue is set for 1 day. Is this a problem with BOINC or Einstein? Any way to correct it?
Too many units downloaded
)
Try decreasing your queue setting. (.25 to .1) For a slow machine that's on only half the time, it will be tough to crunch on a project like Einstein that has short time limits.
> My queue is set for 1
)
> My queue is set for 1 day.
It's a BOINC problem, I believe, since BOINC handles the scheduling of work. People are working on trying to improve this but, really, your best option is to reduce the queue right down.
Your box takes approximately 23 hours. With a 30% share, E@H is only getting 3.6 hours of your 12 hr day. Even if you set the queue at 0.05, the system will download more work when you still have 1-2 hours remaining on the current job so that the new work will still be effectively a good part of a "day" old before it starts to run. For that reason, I'd suggest setting your queue to no more than 0.1. If you set it at 0.25 (ie 6 hrs) you will have 2 "day" old work before it even gets to start. The five days left will probably not be sufficient to complete the work in time.
If you wish to continue with E@H and not risk losing work to deadlines, you have basically two choices. Either set the queue to as low as possible (eg 0.05) to delay new work as long as possible or increase the resource share for E@H a little bit. There is a third choice and this is a personal one. Allow your box to run longer than 12 hours :).
Cheers,
Gary.
> > My queue is set for 1
)
> > My queue is set for 1 day.
>
What is strange is that even when there is less than 1 hour remaining on the current work no new work will download. I get a message saying it would not complete in time. But when a new unit starts I get more work downloaded within the first few minutes.
> What is strange is that
)
> What is strange is that even when there is less than 1 hour remaining on the
> current work no new work will download. I get a message saying it would not
> complete in time. But when a new unit starts I get more work downloaded within
> the first few minutes.
I don't really understand what you're now saying. At the moment your queue shows two work units and I presume one of those is part way through processing. Surely you're not expecting a third to be downloaded before the first finishes??
Can you let us know the current value of the "connect to network" interval and when you last changed it? Did you do an "update" after you last changed it? Nothing happens with prefs changes until an "update" occurs, normally when your client next makes contact with the scheduler unless you force one manually.
Cheers,
Gary.
> > I don't really
)
>
> I don't really understand what you're now saying. At the moment your queue
> shows two work units and I presume one of those is part way through
> processing. Surely you're not expecting a third to be downloaded before the
> first finishes??
>
> Can you let us know the current value of the "connect to network" interval and
> when you last changed it? Did you do an "update" after you last changed it?
> Nothing happens with prefs changes until an "update" occurs, normally when
> your client next makes contact with the scheduler unless you force one
> manually.
>
My connect to network interval is 1 day and has been set to that for more than a month. The problem is that a second work unit downloads while there is still 5 days left before the current one completes. The second one will not start until just before it expires. Once a work unit runs for a while there is no problem. I only seem to have a proble with an extra downloading during the first few minutes of a new unit.
> My connect to network
)
> My connect to network interval is 1 day and has been set to that for more than
> a month. The problem is that a second work unit downloads while there is still
> 5 days left before the current one completes.
This was all explained in a previous message. It is your decision to give E@H approximately 3.6 hours of time every 24 hours of wall clock time. That's what a resource share of 30% of a 12 hour working day gives you. A result takes 23 hours to complete. If you have a second work unit on hand before the first one gets to within 3.6 hours (ie 1 wall clock day) of completion, it physically can't be done before the deadline because it needs 23/3.6 = 6.4 days to rack up the 23 hours for completion and 6.4 + 1 is greater than 7.
However you are telling BOINC that you want a minimum cache size of 1 day and BOINC cannot know how many hours per day you will be running your box so it assumes 24. There are also other aspects that BOINC tries to calculate so as to know when to get more work. For example, it doesn't properly take into account the other projects you are running. Everybody's experience is that you will always get more work than you bargain for so you need to adjust for this by lowering your "connect to network" interval. You need to delay the downloading of the second work unit to as late a stage as possible and 0.05 to 0.1 will hopefully do that for you.
I know you don't want to do that for fear that your main project will go down and you will run out of work but you are protected to some extent by supporting multiple projects. Why don't you try something a lot lower than 1.0 and see what happens? You can always increase it again if you're not happy.
Cheers,
Gary.