We have to oddly make a `StoreConfig` subclass to get it, but
https://github.com/NixOS/nix/pull/9848 will fix that.
The purpose of this is to ensure that, absent an explicit config,
`localhost` includes `ca-derivations` and `recursive-nix` if those
experimental features are enabled.
Very much the complement of #1342, the previous PR.
A slight dedup, and also ensures that floating CA derivations require a
`ca-derivations` experimental feature. This fixes the scheduling issue
that @SuperSandro2000 found.
This is *just* using the fields from that type, and only where the types
coincide. (There are two fields with different types, `speedFactor` most
interestingly.) No code is reused, so we can be sure that no behavior is
changed.
Once the types are reconciled on the Nix side, then we can start
carefully actually reusing code.
Progress on #1164
Instead of doing this partial operation a number of times, assert (with
a comment, get a reference to the thing inside, and use that just once.
(This refactor was done twice, "just once" for each time.)
It has a performance cost, and as the comment says we should be doing
the better solution. We want to land this preparatory change on prod
while the rest is still on staging, so we should just skip it for now.
Skipping it will not affect regular fixed-output and input-addressed
derivations, which are the only ones prod would deal with upon getting
this code.
The main CA derivations support branch will revert this commit so it
still works.
For the record, here is the Nix 2.19 version:
https://github.com/NixOS/nix/blob/2.19-maintenance/src/libstore/serve-protocol.cc,
which is what we would initially use.
It is a more complete version of what Hydra has today except for one
thing: it always unconditionally sets the start/stop times.
I think that is correct at the other end seems to unconditionally
measure them, but just to be extra careful, I reproduced the old
behavior of falling back on Hydra's own measurements if `startTime` is
0.
The only difference is that the fallback `stopTime` is now measured from
after the entire `BuildResult` is transferred over the wire, but I think
that should be negligible if it is measurable at all. (And remember,
this is fallback case I already suspect is dead code.)
This is just C++ changes without any Perl / Frontend / SQL Schema
changes.
The idea is that it should be possible to redeploy Hydra with these
chnages with (a) no schema migration and also (b) no regressions. We
should be able to much more safely deploy these to a staging server and
then production `hydra.nixos.org`.
Extracted from #875
Co-Authored-By: Théophane Hufschmitt <theophane.hufschmitt@tweag.io>
Co-Authored-By: Alexander Sosedkin <monk@unboiled.info>
Co-Authored-By: Andrea Ciceri <andrea.ciceri@autistici.org>
Co-Authored-By: Charlotte 🦝 Delenk Mlotte@chir.rs>
Co-Authored-By: Sandro Jäckel <sandro.jaeckel@gmail.com>
The previous implementation was O(N²lg(N)) due to sorting the full
runnables priority list once per runnable being scheduled. While not
confirmed, this is suspected to cause performance issues and
bottlenecking with the queue runner when the runnable list gets large
enough.
This commit changes the dispatcher to instead only sort runnables per
priority once per dispatch cycle. This has the drawback of being less
reactive to runnable priority changes: the previous code would react
immediately, while this might end up using "old" priorities until the
next dispatch cycle. However, dispatch cycles are not supposed to take
very long (seconds, not minutes/hours), so this is not expected to have
much or any practical impact.
Ideally runnables would be maintained in a sorted data structure instead
of the current approach of copying + sorting in the scheduler. This
would however be a much more invasive change to implement, and might
have to wait until we can confirm where the queue runner bottlenecks
actually lie.
We were using protocol version 6 but requesting version 4. The only
reason that this worked was because of a broken version check in
'nix-store --serve'. That was fixed in
c2d7456926,
which had the side-effect of breaking hydra-queue-runner.
NOTE: I'm well-aware that we have to be careful with this to avoid new
regressions on hydra.nixos.org, so this should only be merged after
extensive testing from more people.
Motivation: I updated Nix in my deployment to 2.9.1 and decided to also
update Hydra in one go (and compile it against the newer Nix). Given
that this also updates the C++ code in `hydra-{queue-runner,eval-jobs}`
this patch might become useful in the future though.
