Re: guix pull timing out on low resource servers

[ng0 <ng0@pragmatique.xyz>]

On Mon, 15 May 2017, ng0 wrote:

> On Mon, 15 May 2017, Andy Wingo wrote:
>
>>  On Mon 15 May 2017 12:12, ng0 <ng0@pragmatique.xyz> writes:
>>
>>>  Since the switch to Guile 2.2 and guix pull taking much more
>>>  computing time and resources, all my virtual hosting servers
>>>  time out when I run guix pull on them without using mosh
>>>  and just openssh, because the process just takes much too
>>>  long.
>>>
>>>  I doubt I'm the only one who experiences this, and just
>>>  increasing the server specs for this process is pointless
>>>  for what they run.
>>>  It's even worse than that, in the future there will be just
>>>  one DNS server running GuixSD, this requires minimal resources.
>>>  Should I just never update these devices or "just get a real
>>>  server"?
>>
>>  I have the smallest DigitalOcean droplet size with a swap partition, and
>>  things work for me I think.  Takes a while though.
>>
>>  There will always be some machines that won't be able to "guix pull"
>>  because of resource constraints.  But I think they are in a minority and
>>  they don't include e.g. the smallest DigitalOcean droplets.
>>
>>  In the meantime we need to rework "build-all.scm" I think to not incur
>>  an O(N) memory usage in the size of the guix package set by
>>  topologically sorting the files (I know there are cycles, but the
>>  general approach should improve things), and by forking off and
>>  compiling the files in separate processes instead of doing everything
>>  from one process (albeit with many threads).  Additionally there are
>>  some compiler speedups in Guile to be had (notably the "basic register
>>  allocation" task from
>>  https://wingolog.org/archives/2016/02/04/guile-compiler-tasks).
>>
>>  And in the meantime-meantime, the workaround is to use a swap file that
>>  is as large as necessary.
>>
>>  Andy
>
> server 1: 1024MB RAM, 2048MB Swap, 4 cores.

actually: 512MB RAM, 1024MB Swap.

> server 2: 512MB RAM, 4096MB Swap, 2 cores.
>
> Didn't fail before.. of course I can try to increase the swap, but I doubt 
> that this really help.
>
> Both systems were able to pull before we used 2.2
>
> I even compiled most of the system on one of them as substitutes weren't 
> available, so resources aren't the problem.
>

Great Scot… I recommend to create at least an 2.2GiB Swapfile when you run 
Guix on a virtualized machines (in case they don't have access to full 
CPUs on their own. Be prepared for over 12 hours of 'guix pull' on those 
low specs servers with the recent move to Guile 2.2, compared to just a
couple of hours on bare metal.