[distcc] distcc over slow net links

[Martin Pool]

On Mon 2003-08-25, Dag Wieers wrote:

> The way I thought Timothee meant it, was like this:
> 
> 	Whenever a host has finished processing jobs and distcc (make)
> 	is out of jobs but still waiting for results on some jobs. It
> 	could resend the (already preprocessed) jobs to any idle
> 	machines and use the result from the fastest machines that can
> 	deliver it. (and finish the other ones)
> 
> Of course this means that the distcc instances have to have some
> shared knowledge about what jobs are still ongoing and access to
> preprocessed output.
> 
> But I like the idea, especially in environments where some of the
> servers in your cluster are sometimes used for heavy duty. If you're
> waiting, you might as well bet on another horse (especially when it is
> at no extra cost)

But there is a cost: other jobs which might arrive in the future or
which might be sent by another user will not be able to use those
servers.  So we want to do this only when the possible gain is so great
as to justify the risk.  

One can imagine a naive algorithm wasting a lot of time.

To turn the question around: why don't we just schedule the job on the
nearby machine in the first place?

-- 
Martin