[distcc] Loadbalanced distcc

[Patrik Olesen]

Dan Kegel wrote:

>On 1/5/06, Victor Norman <vtnpgh at yahoo.com> wrote:
>  
>
>>The nice things about dmucs are:
>>
>>o if other engineers are using the compile machines for other tasks, the
>>loadavg daemons will communicate the loads to the dmucs server, and those
>>machines will be used less often for compiles -- so my system takes into
>>account not just loadavg based on number of compiles on a machine, but on
>>other factors as well.
>>    
>>
>
>This is a very good thing.
>I have an alternative approach which achieves
>part of this benefit without requiring a central server.
>The idea is, the user invokes 'make' via a wrapper
>that runs a client-side program which queries all
>the servers in parallel to see how quickly they respond to a compile
>request for 'hello, world'.  Servers that respond promptly
>are added to the host list for the current make job.
>This lets you avoid machines which are loaded down or otherwise having problems.
>It's not as good as dmucs, but it's quite useful.
>
A third approach could be to use the same idea as in dmucs, but let all 
the servers send the loadavg as a multicast instead of a unicast. This 
will allow all machine in the cluster to have its own db.

The advantage will be that we have a distributed load-db and the client 
does not need to send a tcp-question for each file to compile.

The disadvantage could be higher netload on slow machines since all 
loadavg messages need to be handled, perhaps this could be benchmarked?

/ Patrik