If there is anything I can do to help test, please let me know...

David Anderson wrote:
> I just checked in the change you describe.
> Actually it was added 4 years ago,
> but was backed out because there were reports that it wasn't working right.
> 
> This time I added some <file_xfer_debug>-enabled messages,
> so we should be able to track down any problems.
> 
> -- David
> 
> Lynn W. Taylor wrote:
>> Hi All,
>>
>> I've been watching s...@home during their current challenges, and I 
>> think I see something that can be optimized a bit.
>>
>> The problem:
>>
>> Take a very fast machine, something with lots of RAM, a couple of i7 
>> processors and several high-end CUDA cards -- a machine that can chew 
>> through work units at an amazing rate.
>>
>> It has a big cache.
>>
>> As work is completed, each work unit goes into the transfer queue.
>>
>> BOINC sends each one, and if the upload server is unreachable, each 
>> work unit is retried based on the back-off algorithm.
>>
>> If an upload fails, that information does not affect the other running 
>> upload timers.
>>
>> In other words, this mega-fast machine could have a lot (hundreds) of 
>> pending uploads, and tries every one every few hours.
>>
>> I see two issues:
>>
>> 1) The most important work (the one with the earliest deadline) may be 
>> one of the ones that tries the least (longest interval).
>>
>> 2) Retrying 100's of units adds load to the servers.  180,000-odd 
>> clients trying to reach one or two machines at SETI.
>>
>> Optimization:
>>
>> On a failed upload, BOINC could basically treat that as if every 
>> upload timed out.  That would reduce the number of attempted uploads 
>> from all clients, reducing the load on the servers.
>>
>> Of course, since the odds of a successful upload is just about zero 
>> for a work unit that isn't retried, by itself this is a bad idea.
>>
>> So, when any retry timer runs out, instead of retrying that WU, retry 
>> the one with the earliest deadline -- the one at the highest risk.
>>
>> As the load drops, work would continue to be uploaded in deadline 
>> order until everything is caught up.
>>
>> I know a project can have different upload servers for different 
>> applications, or for load balancing, or whatever, so this would only 
>> apply to work going to the same server.
>>
>> The same idea could apply to downloads as well.  Does the BOINC client 
>> get the deadline from the scheduler??
>>
>> Now, if I can figure out how to get a BOINC development environment 
>> going, and unless it's just a stupid idea, I'll be glad to take a shot 
>> at the code.
>>
>> Comments?
>>
>> -- Lynn
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> 
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