[distcc] using a powerful build host

[Martin Pool]

On 17 Nov 2002, Andi Kleen <ak at muc.de> wrote:

> I normally compile on the workstation but sometimes when I'm in a hurry
> and need a big tree rebuilt I want to tap the power of the multi processor
> box using distcc.
> 
> What I tried: 
> 
> just specify DISTCC_HOSTS=mpbox CC="distcc gcc" make -j8 ... 
> 
> Unfortunately top on mpbox shows that only one or two cc1s are active 
> in parallel. I also tried DISTCC_HOSTS="mpbox mpbox ..." (8 times) ... -j8,
> but it also doesn't seem to trigger much more parallelism. The makefiles
> are set up for parallelism, when I run it locally on the mpbox it
> runs much faster.

Repeating the hostname won't make any difference with the current
code.

You might like to check that you're using 0.14, because 0.13 had a bug
that caused at most 4 jobs to run at once anywher.e  

> I'm considering now to configure multiple IP aliases and run 
> 8 distccs in parallel on the mpbox.

That might help, but it shouldn't really be needed.  

Could you send me (off the list) a copy of the verbose client and
server logs for a representative subset of the compile (building 40-50
files, maybe?)  That might help me work out why it's not doing more
work remotely.

It's most likely to be an inefficiency in the (still simple-minded)
scheduler, but it may be that the network between the two machines is
saturated.

> Is there are a better way to do what I want?

I don't know of one yet, but with the logs hopefully I can give you a
workaround or fix.

-- 
Martin