Re: 03/03: hydra: Update the file with the machines in the bayfront build farm.

Re: 03/03: hydra: Update the file with the machines in the bayfront build farm.

[Ludovic Courtès]

Hi!

andreas@enge.fr (Andreas Enge) skribis:

> --- a/hydra/machines-bayfront.scm
> +++ b/hydra/machines-bayfront.scm
> @@ -5,7 +5,7 @@
>      (user "bayfront")
>      (host-key "ssh-ed25519 AAAAC3NzaC1lZDI1NTE5AAAAIBfd3VZqyoKoZG3X772eDBrN2MPhnNDDnVA34hpf0f9b root@(none)")
>      (parallel-builds 3)
> -    (speed 1.0)))
> +    (speed 8.0)))
>      
>  (define milano
>    (build-machine
> @@ -14,17 +14,17 @@
>      (user "bayfront")
>      (host-key "ssh-ed25519 AAAAC3NzaC1lZDI1NTE5AAAAIPJFpBJSaOK2aDaR48Fm8udhLK9fl5YwNlq43uaLBeRv root@(none)")
>      (parallel-builds 3)
> -    (speed 1.0)))
> +    (speed 32.0)))

‘speed’ should be used with care: in general, you always want it to be
the same (not to be confused with ‘parallel-builds’).  In the case
above, the risk is that milano will always be chosen.

When milano’s load is too high, it’ll fall back to the next machine, but
then it means scheduling is wasting time always contacting machines in
the same order, which goes against the strategy of
‘choose-build-machine’ in (guix scripts offload).

Maybe acceptable when there are few machines, but otherwise not great.
:-)

Ludo’.

Re: 03/03: hydra: Update the file with the machines in the bayfront build farm.

[Andreas Enge]

Hello!

On Sun, Sep 20, 2020 at 03:22:25PM +0200, Ludovic Courtès wrote:
> ‘speed’ should be used with care: in general, you always want it to be
> the same (not to be confused with ‘parallel-builds’).  In the case
> above, the risk is that milano will always be chosen.

See https://issues.guix.gnu.org/43773 .

Once this is fixed, I agree.

Andreas