57 beta cycle: 57beta/devedition published earlier + soft freeze

[Sylvestre Ledru]

Hello,

tldr: we are going to do a first merge of m-c => m-b and use the
devedition population one week earlier to push 57.0b1 & 57.0b2.

In order to maximize beta testing, we are going to take advantage of the
fact that we have a different set of users with the developer edition
(which is, since the completion of the dawn project, based on mozilla-beta).
September 14th, we will merge mozilla-central => mozilla-beta and
mozilla-beta => mozilla-release. September 19th, we will push to the
devedition population the first beta of 57. Later, we will be pushing a
second beta to this channel.
In parallel, to minimize the impact on the developer, mozilla-central
will remain 57.0a1 and will be merged to mozilla-beta transparently.
Nightly will become 58.0a1 on September 21th.
The regular beta population will remain on 56 and will be provided
updates to the RC builds.

The milestones are detailed in this Google doc:
https://docs.google.com/document/d/1jeypuqBqEyIh-4qxXT0UnE2aVjetN7uVD8W7L7TbWKg/edit

In parallel, as the soft freeze demonstrated its value during previous
cycles, we are going to use this again during the 57 nightly cycle. From
September 18th, we will ask you to land only bug fixes, stability or
important performance fixes. New development not planned for 57 should
land once mozilla-central will become 58 (September 21th).

Thanks,
Sylvestre

[Ed Lee]

Is there any guidance on when commits should make it to autoland and
inbound for both Merge Days (14th and 21st)? I suppose people should just
get things in 24 hours before midnight 00:00 Pacific Time to be "safe" in
case there's any bustages (hopefully reduced with the soft freeze).

For some context from 56 Merge Day (August 2nd), the last autoland commit
that made it to Beta 56 was from August 1st 06:49 Pacific, and the last
inbound commit was from 14:12. mozilla-central was tagged at August 2nd
00:35. In this case, autoland had an ~18 hour earlier cutoff and inbound
had a ~10 hour earlier cutoff to "make it" without needing
approval-beta-56. There were 176 bugs that landed on autoland [1] or
inbound [2] while it was still "August 2nd Pacific", and 44 (25%) of those
were uplifted. (I suppose not auto-uplifting the other 75% might be worth
the overhead of additionally requesting+approving 10% of the 445 bugs
uplifted to 56.)

Ed Lee

[1]
https://hg.mozilla.org/integration/autoland/pushloghtml?startdate=2017-08-01+13%3A50&enddate=2017-08-03+07
[2]
https://hg.mozilla.org/integration/mozilla-inbound/pushloghtml?startdate=2017-08-01+21%3A13&enddate=2017-08-03+07

--
Ed Lee

[Ryan VanderMeulen]

In general, I would say your best bet is to have patches landed by mid-day
PDT the day before if you want to be reasonably confident that it'll get
merged over to Beta in time. Predicting when merges will happen is
difficult due circumstances like build/test failures, infra issues, etc.
It's possible that there will be a final set of autoland/inbound merges to
m-c on those days ahead of the merge to Beta, but I wouldn't assume they'll
happen either.

-Ryan

[Kim Moir]

Several releng folks, RyanVM and jcristau had a meeting today discussing
tomorrow's merge

We wanted to ensure that we would be able to have the correct branding for
Fennec beta after the merge. In order to do this, we will have a relbranch
created for Fennec on Sept 14 named FIREFOX_56b13_RELBRANCH. We'll use
this branch to build Fennec 56.0b13 on Sept 18. This process will look like
this:

Sept 13th:

-

GTB: Desktop and DevEdition 56.0b12

Sept 14:

-

Releng Migration
-

RyanVM: Create FIREFOX_56b13_RELBRANCH on m-b out of
FIREFOX_BETA_56_END and manually bump version number to 56.0b13.
-

Approved patches for 56 will be landed on both mozilla-release
(default branch) and mozilla-beta (FIREFOX_56b13_RELBRANCH).
-

Merge m-b->m-r normally. All tags will be made. Version numbers will
be bumped. Branding will be release.
-

Merge m-c->m-b


-

No action on m-c.
-

Prior to m-c->m-b script run, comment out: https://dxr.mozilla.org/
mozilla-central/source/testing/mozharness/scripts/
merge_day/gecko_migration.py#329-336
<https://dxr.mozilla.org/mozilla-central/source/testing/mozharness/scripts/merge_day/gecko_migration.py#329-336>
-

Or undo those steps after the run


Between sept 14->21

-

GTB: DevEdition 57.0b1, sometimes this week, off mozilla-beta default
-

Uplifts: Regular merges will happen between still 57 m-c, to m-b.
Preferably once a day.
-

Uplifts: Regular uplifts will happen to 56 m-r (and need to be
backported to fennec 56 branch on m-b)


Sept 18th

-

GTB: Desktop 56.0rc1 off m-r default
-

GTB: Fennec 56.0b13 off m-b FIREFOX_56b13_RELBRANCH


The discussion is summarized in this document at the end under "Releng
actions"

https://docs.google.com/document/d/1SRjdBNjj4LM0IV4vs1UMrPnp
yhyNTYpJLZhLHg2TZI8

Kim