Hi, Leo Famulari <l...@famulari.name> skribis:
> On Sat, Nov 09, 2019 at 06:40:56PM +0100, Ludovic Courtès wrote: >> Like I wrote, it’s not that simple (we’d first need the daemon to >> distinguish substitution jobs from other jobs, but note that there are >> also “downloads” that are actually derivation builds), and it’s not >> clear to me that it’s overall beneficial anyway: it’s not supposed to be >> faster to download 10 things in parallel from ci.guix.gnu.org, than to >> download them sequentially. > > Parallel downloading is not faster in terms of overall transfer rate > from ci.guix.gnu.org. > > However, installing things with Guix involves downloading a lot of very > small files like derivations, and Guix spends a lot of time initiating > these downloads. Good point. Note that .drv files are never downloaded, but nevertheless it’s true that there are often small files like the “module-import-compiled” things. This happens when building a system, but not so much when building a package, though. > For example, I can download things at 100 megabits, but when Guix needs > to sequentially download 50 10-kilobyte files, it may take an entire > minute. > > So there is a huge speedup with parallel downloading. One thing I’d like to get rid of is the initial HTTP GET for /nix-cache-info which is completely useless now. That could help a bit. Thanks, Ludo’.