Having a hundred threads doing I/O at the same time is bad on magnetic
disks because of the excessive disk seeks. So allow only 4 threads to
copy closures in parallel.
While sorting machines by load, the load of a machine
(machine->currentJobs) can be changed by other threads. If that
happens, the comparator is no longer a proper ordering, in which case
std::sort() can segfault. So we now make a copy of currentJobs before
sorting.
There is a slight possibility that the queue monitor and a builder
thread simultaneously decide to mark a build as finished. That's fine,
as long as we ensure the DB update is idempotent (as ensured by doing
"update Builds set finished = 1 ... where finished = 0").
If a build A depends on a derivation that is the top-level derivation
of some build B, then we should process B before A (meaning we
shouldn't make the derivation runnable before B has been
added). Otherwise, the derivation will be "accounted" to A rather than
B (so the build step will show up in the wrong build).
Aborted builds are now put back on the runnable queue and retried
after a certain time interval (currently 60 seconds for the first
retry, then tripled on each subsequent retry).
Hydra-queue-runner now no longer polls the queue periodically, but
instead sleeps until it receives a notification from PostgreSQL about
a change to the queue (build added, build cancelled or build
restarted).
Also, for the "build added" case, we now only check for builds with an
ID greater than the previous greatest ID. This is much more efficient
if the queue is large.
It just makes things unnecessarily complicated. We can just exit
without cleaning anything up, since the only thing to do is unmark
builds and build steps as busy. But we can do that by having systemd
call "hydra-queue-runner --unlock" from ExecStopPost.
If multiple threads create a step for the same build, they could get
the same "max(stepnr)" and allocate conflicting new step numbers. So
lock the BuildSteps table while doing this. We could use a different
isolation level, but this is easier.
This removes the need for Nix's build-remote.pl.
Build logs are now written to $HYDRA_DATA/build-logs because
hydra-queue-runner doesn't have write permission to /nix/var/log.
When visiting the tail-reload page, for a short amount of time the
"unscrolled" version is shown. To circumvent that, let's scroll down
immediately at the first possibility to fill the gap between the loading
of the document and the first AJAX request coming in.
Signed-off-by: aszlig <aszlig@redmoonstudios.org>
There are quite a lot of build outputs which have lines with a length
exceeding the width of the taillog <pre/> and thus visually produce more
lines than 50. This causes the tail "box" to change height frequently
and to get to the bottom you need to scroll down.
We now set a fixed line-height to 120% of the font size and cap the
maximum height based on that value (50 * 1.2 = 60). It's probably not
nice to override the line-height, but max-lines is currently only
available using browser-specific property names. But after all it's just
for the tail output, if people complain about the line-height, we can
still change it :-)
Signed-off-by: aszlig <aszlig@redmoonstudios.org>
We're just implicitly escaping the tail content by not using .load() but
explicitly setting the text content using .text(), so that escaping
isn't needed on our side.
This should get rid of a few formatting errors and possibly XSS if
someone manages to place JS code in the tail of a build and manages to
lurk a user to that tail output.
Signed-off-by: aszlig <aszlig@redmoonstudios.org>
