Re: Questions regarding offloading ( unprivileged setup , parallel builds )

[ludo@gnu.org (Ludovic Courtès)]

Hello,

YOANN P <yoann_mac_donald@hotmail.com> skribis:

> I didn't find any documentation describing a way to use an alternative file for the offload settings instead of the default /etc/guix/machines.scm.
>
>
> Did i missed something ?

No, this is correct.

> Is there other files that are put under /etc ?

/etc/guix also contains things related to substitutes.

> It could be problematic for users who use custom store/state path in unprivileged environnements but want to use the offload isn't it ?

Indeed, though if you’re customizing things anyway, you could run:

  ./configure --prefix=/my/prefix --sysconfdir=/my/etc

> Another question regarding the offload, how are used the machines describe inside  /etc/guix/machines.scm ?
>
> If the installation of a package require to build multiple packages, does the builds are all done on the first machine choose for the build or distribute over all machines describe on /etc/guix/machines.scm ?

When there are several matching machines, ‘guix offload’ currently picks
one at random; if that machine is already under high load, it goes on
and picks another one.  See:

  https://git.savannah.gnu.org/cgit/guix.git/tree/guix/scripts/offload.scm#n442

> The description of "parallel-builds" parameter and the fact than missing dependencies already present on the host who request the offload seem to be transferred through ssh let me think that only one machine at time is used for the offload even if all the machines present inside machines.scm share the same store.

Several machines can be used at the same time, no worries.  :-)

> Not sure about this too, there is no ssh transfert if the dependencies (same packages / store path ) are already on the offload store isn't it ?

Right, only missing items are transferred.

> Implementing something similar to the project "guix-relocate" from Pjotr inside the core project to be able to use native Guix packages with custom path when we install them would be a real huge improvement to prevent the use of proot/namespace/offloading :)

I think offloading serves a completely different purpose: it’s a way to
distribute builds to several machines.

But yeah, we discussed relocation at FOSDEM again and it’s a useful
thing in its own right, even though there are limitations.  :-)

Ludo’.