This allows checking a jobset (say) at most once a day. It's also
possible to disable polling by setting the interval to 0. This is
useful for jobsets that use push notification or are manually
evaluated.
This reverts commit 71d020735b.
Unfortunately there are still some cases where we need to set Hydra's
concurrency separately. (Ideally, Hydra would start *all* queued
builds in parallel and let Nix take care of everything...)
External machines can now notify Hydra that it should check a
repository by sending a GET or PUSH request to /api/push, providing a
list of jobsets to be checked and/or a list of repository URLs. In
the latter case, all jobsets that have any of the specified
repositories as an input will be checked.
For instance, you can configure GitHub or BitBucket to send a request
to the URL
http://hydra.example.org/api/push?repos=git://github.com/NixOS/nixpkgs.git
to trigger evaluation of all jobsets that have
git://github.com/NixOS/nixpkgs.git as an input, or to the URL
http://hydra.example.org/api/push?jobsets=patchelf:trunk,nixpkgs:trunk
to trigger evaluation of just the specified jobsets.
It's pointless to store these, since Nix knows where the logs are.
Also handle (in fact require) Nix's new log storage scheme. Also some
cleanups in the build page.
* Don't use isCurrent anymore; instead look up builds in the previous
jobset evaluation. (The isCurrent field is still maintained because
it's still used in some other places.)
* To determine whether to perform an evaluation, compare the hash of
the current inputs with the inputs of the previous jobset
evaluation, rather than checking if there was ever an evaluation
with those inputs. This way, if the inputs of an evaluation change
back to a previous state, we get a new jobset evaluation in the
database (and thus the latest jobset evaluation correctly represents
the latest state of the jobset).
* Improve performance by removing some unnecessary operations and
adding an index.
The hydra-update-gc-roots script is taking around 95 minutes on our
Hydra instance (though a lot of that is I/O wait). This patch
significantly reduces the number of database queries. In particular,
the N most recent successful builds for each job in a jobset are now
determined in a single query. Also, it removes the calls to
readlink().
Prepared statements are sometimes much slower than unprepared
statements, because the planner doesn't have access to the query
parameters. This is the case for the active build steps query (in
/status), where a prepared statement is three orders of magnitude
slower. So disable the use of prepared statements in this case.
(Since the query parameters are constant here, it would be nicer if we
could tell DBIx::Class to prepare a statement with those parameters
fixed. But I don't know an easy way to do so.)
For schema upgrades, hydra-init executes the files
src/sql/upgrade-<N>.sql, each of which upgrades the schema from
version N-1 to N. The upgrades are wrapped in a transaction.
The singleton table SchemaVersion contains the current version
of the Hydra database schema. This can be used to upgrade the
schema on the fly.
Also reran the DBIx::Class schema loader.
* Store the system type in the BuildSteps table.
* Don't query the queue size when serving static pages. This prevents
two unnecessary database queries per request.
