Hi! Leo Famulari <l...@famulari.name> skribis:
> I noticed that in many cases, it takes longer to set up the substitution > than to actually download the substitute on my 30 Mbps downlink. Yeah. > The effect is that it might take a few minutes to to download a few > dozen small substitutes, which may only total 5 megabytes of data, even > though my connection to the substitute server is fast enough that it > should only take a few seconds. > > So, it benefits me to increase max-jobs for substitute downloads. > However, I rarely want to actually build packages in parallel; one > package build may fully load my system. > > Currently, is it possible to distinguish between substitute downloads > and builds? Maybe it would be an overall performance win to download > substitutes in parallel, in tune with parallel-job-count. No, they cannot be distinguished. I’d be in favor of a solution where ‘guix substitute’ is kept alive across substitutions (like what happens with ‘guix substitute --query’), which would allow it to keep connections alive and thus save the TLS handshake and a few extra round trips per download. Thoughts? Ludo’.
