596748 - Clobber at the end of a try server build to improve end-to-end times

Status: RESOLVED DUPLICATE of bug 712206

(Release Engineering :: General, defect, P4)

Description

[John Ford [:jhford] CET/CEST Berlin Time]

Because we know that we are clobbering try server builds, we should clobber at the end of the build instead of at the beginning (or do both, making one trivially short).  If we were to do this, we would improve our push to test results available time.  This should not have an effect on the time of the build job so it shouldn't hurt our build wait times.

The main drawback here is that we wouldn't save the build directory.  I don't know how big of a concern this is because the slave will pick up a new job right after reboot which will do a clobber.  If this is a real concern, we could gate the clobber at the end of the build on a file being present on the filesystem.  If we made sure that buildbot.tac was called buildbot.tac before the second clobber, we could roughly duplicate current behaviour.

Comment 1

[Chris Cooper [:coop] (he/him)]

(In reply to comment #0)
> Because we know that we are clobbering try server builds, we should clobber at
> the end of the build instead of at the beginning (or do both, making one
> trivially short).

As we discussed elsewhere, it behooves us to do both (just in case), but yes, the one at build start should be essentially a no-op.

Comment 2

[John Ford [:jhford] CET/CEST Berlin Time]

we could also do this for nightlies

Comment 3

[Nick Thomas [:nthomas] (UTC+12)]

(In reply to comment #2)
> we could also do this for nightlies

We already do actually, to free up the space for other builds.

Comment 4

[Chris AtLee [:catlee]]

alternately we could clobber before starting buildbot

Comment 5

[[e-mail] (:bhearsum)]

Slave pre flight tasks are going to handle this.