R.I.P. Carroll Shelby

On Thursday, 10-may-2012, Caroll Shelby died, aged 89.

Originally a chicken farmer, he became a race car driver until 1959, when heart problems brought his successful racing career to an end, so he switched again to focus on designing and building powerfully fast, brash, muscle cars that he loved to drive, including some great icons:

AC Cobra/Shelby Cobra

Ford Mustang GT390 (made famous by Steve McQueen in the movie “Bullitt“.)
…and several other

Dodge Viper

Ford GT

Even at 84 years of age, while a consultant on developing the new high-powered Ford GT, he still loved driving fast, and test drove the new Ford Mustang GT500 on a race track at 150mph.

I didnt realize until today that he was also one of the world longest living heart transplant recipients, having received a heart transplant in 1990.

A more detailed bio is available on his Shelby-America company website, on Wikipedia, The New York Times and The Washington Post .

Are you a night owl?

I was not a participant in either of these two medical studies.

Caffeine Disrupts Sleep for Morning People, but Not Night Owls
“…for the early risers, the more caffeine in their bodies, the more time they spent awake during the night after initially falling asleep. This was not seen in the night owls.”

‘Morning people’ and ‘night owls’ show different brain function
“…In morning people their cortical excitability actually decreased throughout the day. It was highest in the morning and lowest in the evening,… It was the opposite for evening people; their brain activity was highest at 9 p.m.”

Those of you who know me, all know that I am a night owl who drinks a lot of coffee, and routinely finishes a pot of coffee before going to sleep. I used to think it was only me. However, after reading these medical studies, I wonder how many others out there are also night owls with a high tolerance for caffeine?

Mozilla’s Release Engineering published in AOSA(vol2)

I’m excited to say that The Architecture of Open Source Applications (vol2) is now available.

This book is a collection of great chapters, each written by different people from different aspects of the open source world. For armenzg, catlee, lsblakk and myself, this was a great opportunity to write a chapter describing the release automation behind Mozilla’s Firefox.

If you were ever curious about the process (and the code!) that allow us to do things like sim-ship a Firefox release in 93 locales, or lets us ship 8 emergency chemspill releases in 42 hours, then please have a read. Hopefully, this might also help others who are doing release automation at scale for other products. If you find a typo in the book, or something that you think could be improved in our automation, please be kind and let us know.

Our release automation constantly evolves, as new product requirements arise or we find new ways to obsessively streamline things, so it’ll be interesting to see how this chapter holds up over time.

In addition to the print version (buy here), the book will soon also be available for purchase as a PDF, for purchase as ebook from Amazon and as a free html download (links coming). All royalties go to Amnesty International.

Big thanks to Greg Wilson and Amy Brown who did a great job of making all this happen, explaining mysteries of the book publishing world to us, and generally cat herding armenzg, catlee, lsblakk and myself through the publishing process, within deadlines, all while also doing our “day jobs” at Mozilla.

(Interesting coincidence: kmoir, who recently joined us at Mozilla’s RelEng, is an author of a chapter in the earlier Architecture of Open Source Applications (vol1) – another interesting read.)

Thank you Armen, Chris and Lukas for helping make this book a reality.

40,207 test jobs in a 24 hour day

On 03-may-2012, RelEng infrastructure processed over 40,000 test jobs in a 24 hour day. 40,207 to be precise.

For comparison, 30,000 test jobs a day was a big milestone for us only 5 months ago (09-dec-2011). The milestone of 20,000 test jobs a day was only two months before that (19-oct-2011).

The initial value of ~100 for May2007 is a complete guess on how many test jobs our 2?3? test machines could handle back then when I first started at Mozilla, in between starting to bring up unittest automation, all the tree closures, and needing to rebuild-firefox-as-part-of-tests. Even if the initial value is slightly wrong, the order of magnitude is right. The gap since from 2007-2010 is because we did not have any metrics in place.

#test jobs in a day

Exciting stuff!

Infrastructure load for April 2012

NOTE: In April, we lost 20% (6 of 30 days) of metrics data during the switchover of the backend databases from sjc1 to scl3 data center. Despite missing 20% of the entire month’s data, we still recorded more jobs in April then entire November2011 or entire December2011.

  • #checkins-per-month: April looks like a drop, with “only” 3,327 checkins, but this drop is under-reporting because of the 20% lost data. For comparison, previous records are: March2012 (4,508 checkins), February2012 (4,027 checkins), January2012 (3,962 checkins), December2011 (3,262 checkins), and November2011 (3,209 checkins).
  • #checkins-per-day: We set three new records in April: 280 checkins per-day on 25-apr-2012, along with 278 checkins-per-day on 26-apr-2012, and 246 checkins-per-day on 24-apr-2012.
  • #checkins-per-hour: We peaked at 7.1 checkins-per-hour, which is lower then usual, but to be expected given the lost 20% of data.

mozilla-inbound, fx-team:
mozilla-inbound continues to be heavily used as an integration branch, with 22% of all checkins, by comparison with the fx-team branch (~2% of checkins) or mozilla-central (~4% of checkins).

mozilla-aurora, mozilla-beta:

  • ~3% of our total monthly checkins landed into mozilla-aurora, consistent with previous months.
  • ~1% of our total monthly checkins landed into mozilla-beta, consistent with previous months.

(Standard disclaimer: I’m always glad whenever we catch a problem *before* we ship a release; it avoids us having to do a chemspill release and also we ship better code to our Firefox users in the first place.)

misc other details:

  • Pushes per day

  • Pushes by hour of day