[distcc] Re: distcc and ssh

[Martin Pool]

On 15 Aug 2002, Aaron Lehmann <aaronl at vitelus.com> wrote:

> I think distcc is the coolest thing since distmp3. My computers are
> connected to the internet, but if distcc ran on top of ssh I would use
> it. 

ssh support is certainly on the list.  For the time being you can just
use ssh port forwarding and get most of the benefits.

> I think one major advantage of using ssh to distribute compile jobs
> that I did not see mentioned under the "bugs/missing features"
> section of the documentation for distcc is that sshd allows you to
> run commands from remote hosts, thus AFAICT removing the need to
> install distcc or any other daemon or tools on the compile servers.

I guess you could do everything with only sshd on the compile server
by copying the source across, running the compiler, and then copying
the object back.  Other people have written tools that do that.  It
requires more round trips and possibly would be slower.  I'm not sure
that installing distccd is a great burden.

> If I get the inspiration I may work a bit on SSH support for distcc,
> but I can't promise anything. In particular, giving clients the
> persistence that's necessary for them to hoard connections rather
> than reconnect constantly is practically required but slightly
> tricky. 

Yes, persistence would be nice, though it's not entirely clear that it
is necessary for decent performance.  Certainly you will lose a lot by
using ssh.

> One great side effect of adding some level of persistence to
> distcc is that it would be much easier to hack distcc to always run
> exactly 1 (or more) compiler invocations on each host. 

That's possibly better done in the daemon.

> distcc would be able to queue up files to send to busy remote hosts
> over the persistent SSH connection, and even preprocess new files
> while waiting for remote compiles to finish.

-- 
Martin