bug#53156: GUIX_DAEMON_SOCKET with ssh doesn't cache connections

[Ludovic Courtès]

Hi Efraim,

Should we close this one?

  https://issues.guix.gnu.org/53156

Ludo’.

Ludovic Courtès <ludo@gnu.org> skribis:

> Hi Efraim,
>
> Efraim Flashner <efraim@flashner.co.il> skribis:
>
>> I'm experimenting some more with GUIX_DAEMON_SOCKET, and while when
>> using guix offload I see a socket a /run/user/1000/destination/socket,
>
> What’s this file?
>
>> there's nothing similar when using
>> GUIX_DAEMON_SOCKET=ssh://other-machine. Depending on the machine in
>> question it can take several minutes before a build is started,
>
> That’s because the daemon RPC protocol is suboptimal in that it makes
> lots of round trips, and round trips are very costly over SSH due to
> higher latency.
>
> Eventually we’ll need to adjust/change the protocol, but there’s no
> short-term solution.
>
> (For connections over TCP, ‘open-inet-socket’ in (guix store) uses
> TCP_NODELAY to make this acceptable.  There’s #:nodelay #t in (guix
> ssh), but that doesn’t much as much of a difference.)
>
>> and I'm having a hard time maintaining the connection until the end of
>> a longer build like gccgo.
>
> Is it that the SSH server eventually drop the connection?
>
> HTH,
> Ludo’.