Hello, I was thinking of the memory footprint of bsdiff, and I think it goes quite quite big. So I think that the actual patch system in hydra requires quite a lot of resources, due to the cost of bsdiff specially on big store paths (those where bsdiff would add more benefit, I think).
So, dear Hydra programmers... don't you think there could be a way of using rsync or librsync, and provide a non--simple-HTTP interface to pull storepaths from the build farm to our nixos systems? Although they will not provide the small patches from bsdiff, they will cost much less. For example, I imagine that nixpkgs-unstable contains only, for each system, the latest store paths resulting from nixpkgs evaluation. Nevertheless, hydra holds not only those, but more closures, from previous nixpkgs-unstable manifests; I don't know for how long time. Using an algorithm to decide what common root store paths can be useful (let's say, any shared package with the same name-version) between the farm and the client computer, librsync could reduce a lot the amount of data transfered. I have in mind the regular kde rebuilds we have, due to an update of it or some of its dependencies, and how I would like not to redownload that much (without paying for a faster internet access) I think that such a system, additionally to the rest of the nix system, would look astonishing compared to what other distros have. Any volunteer to start with a hack to test this? Maybe this idea will look nice even for Delft people to implement it. At least I sent this letter before I forget. Regards, Lluís _______________________________________________ nix-dev mailing list nix-dev@cs.uu.nl https://mail.cs.uu.nl/mailman/listinfo/nix-dev
