Builds can now emit metrics that Hydra will store in its database and
render as time series via flot charts. Typical applications are to
keep track of performance indicators, coverage percentages, artifact
sizes, and so on.
For example, a coverage build can emit the coverage percentage as
follows:
echo "lineCoverage $pct %" > $out/nix-support/hydra-metrics
Graphs of all metrics for a job can be seen at
http://.../job/<project>/<jobset>/<job>#tabs-charts
Specific metrics are also visible at
http://.../job/<project>/<jobset>/<job>/metric/<metric>
The latter URL also allows getting the data in JSON format (e.g. via
"curl -H 'Accept: application/json'").
If Hydra isn't hosted on https://example.com/ but something like
https://example.com/hydra/, the URL for /api/scmdiff would have ended up
on /api/scmdiff rather than /hydra/api/scmdiff.
This is because we didn't use the URI resolver from the controller,
hence we're using it now to build up the whole URL including the query
string.
Signed-off-by: aszlig <aszlig@redmoonstudios.org>
Without an index on (machine, stoptime desc), this requires a
sequential scan. And adding a whole index for this seems
overkill. (Possibly the queue runner could maintain this info more
efficiently.)
This prevents a race where multiple threads see that machine X is
missing path P, and start sending it concurrently. Nix handles this
correctly, but it's still wasteful (especially for the case where P ==
GHC).
A more refined scheme would be to have per machine, per path locks.
Derivations with "preferLocalBuild = true" can now be executed on
specific machines (typically localhost) by setting the mandary system
features field to include "local". For example:
localhost x86_64-linux,i686-linux - 10 100 - local
says that "localhost" can *only* do builds with "preferLocalBuild =
true". The speed factor of 100 will make the machine almost always win
over other machines.
