Tuesday, 4 July 2017

Re: Launchpad builders - increasing memory spec

Hi James,

On Tue, Jul 04, 2017 at 04:31:32PM +0000, James Page wrote:
> Hi All

> Mathias and I where discussing some challenges around fitting the Ceph
> build with any level of parallelism in to a virtualized launchpad builder
> (as used for the majority of architectures today).

> Basically the current memory spec only permits a max-parallel of 2 (on
> Xenial amd64). Ceph is a big C++ project so takes some time to build with
> such a low level of parallelism.

> Would it be possible to nudge up the default memory allocation on the
> builders? I use a 16G machine for test builds of i386/amd64 and I've not
> seen any memory exhaustion with parallel=8.

> Or maybe have a mechanism to allow a source package to request a higher
> spec of builder?

You should probably consult the Launchpad team on this, since the Launchpad
builder configuration is owned by them and not by the Ubuntu developers
directly.

As far as raising the default memory allocation, understand that there is a
tradeoff between being able to parallelize /within/ a build and being able
to parallelize across /all/ builds. If the sole justification for this
request is that it would speed up the build of one particular package, I
don't think that's a sufficient reason to reduce the capacity of the
launchpad build farm as a whole.

Providing a mechanism to request a builder of a different size seems ok, but
would need to be designed/implemented in Launchpad; and how do you prevent
this from being abused?

--
Steve Langasek Give me a lever long enough and a Free OS
Debian Developer to set it on, and I can move the world.
Ubuntu Developer http://www.debian.org/
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