Infrastructure load for November 2013

  • We’re back to typical load again in November.
  • #checkins-per-month: We had 7,601 checkins in November 2013. This is our 2nd heaviest load on record, and is back at expected range. For the curious, our heaviest month on record was in August 2013 (7,771 checkins) and our previous 2nd heaviest month was September2013 (7,580 checkins).

    Overall load since Jan 2009

  • #checkins-per-day:Overall load was consistently high throughout the month, with a slight dip for US Thanksgiving. In November, 18-of-30 days had over 250 checkins-per-day, 13-of-30 days had over 300 checkins-per-day, and 1-of-30 days had over 400 checkins-per-day.
    Our heaviest day had 431 checkins on 18nov; close to our single-day record of 443 checkins on 26aug2013.
  • #checkins-per-hour: Checkins are still mostly mid-day PT/afternoon ET. For 10 of every 24 hours, we sustained over 11 checkins per hour. Our heaviest load time this month was 11am-12noon PT 15.6 checkins-per-hour (a checkin every 3.8 minutes!) – slightly below our record of 15.73 checkins-per-hour.

mozilla-inbound, b2g-inbound, fx-team:

  • mozilla-inbound had 16.6% of all checkins. This continues to be heavily used as an integration branch. As developers use other *-inbound branches, the use of mozilla-inbound has reduced over recent months, and is stabilizing around mid-teens of overall usage.
  • b2g-inbound had 11.5% of all checkins. This continues to be a successful integration branch, with usage slightly increased over last month’s 10.3% and a sign that usage of this branch is also stabilizing.
  • fx-team had 6% of all checkins. This continues to be a very active third integration branch for developers. Usage is almost identical to last month, and shows that usage of this branch is also stabilizing.
  • The combined total of these 3 integration branches is 34.1% , which is slightly higher then last month yet fairly consistent. Put another way, sheriff moderated branches consistently handle approx 1/3 of all checkins (while Try handles approx 1/2 of all checkins). The use of multiple *-inbounds is clearly helping improve bottlenecks (see pie chart below) and the congestion on mozilla-inbound is being reduced significantly as people use switch to using other *-inbound branches instead. Overall, this configuration reduces stress and backlog headaches on sheriffs and developers, which is good. All very cool to see working at scale like this.

    Infrastructure load by branch

mozilla-aurora, mozilla-beta, mozilla-b2g18, gaia-central:
Of our total monthly checkins:

  • 2.6% landed into mozilla-central, slightly lower than last month. As usual, most people land on sheriff-assisted branches instead of landing directly on mozilla-central.
  • 1.4% landed into mozilla-aurora, lower then last month’s abnormally high load. This is consistent with the B2G branching, which had B2G v1.2 checkins landing on mozilla-aurora, and now moved to mozilla-b2g26_v1_2.
  • 0.9% landed into mozilla-beta, slightly higher than last month.
  • 0.0% landed into mozilla-b2g18, slightly lower then last month. This dropped to almost zero (total of 8 checkins) as we move B2G to gecko26.
  • 3.3% landed into mozilla-b2g26_v1_2, as part of the B2Gv1.2 branching involving Firefox25. As predicted this is significantly more then last month, and is expected to continue until we move focus to B2G v1.3 on gecko28.
  • Note: gaia-central, and all other gaia-* branches, are not counted here anymore. For details, see here.

misc other details:
As usual, our build pool handled the load well, with >95% of all builds consistently being started within 15mins. Our test pool is getting up to par and we’re seeing more test jobs being handled with better response times. Trimming out obsolete builds and tests continues. As always, if you know of any test suites that no longer need to be run per-checkin, please let us know so we can immediately reduce the load a little. Also, if you know of any test suites which are perma-orange, and hidden on tbpl.m.o, please let us know – those are the worst of both worlds – using up scarce CPU time *and* not being displayed for people to make use of. We’ll make sure to file bugs to get tests fixed – or disabled – every little bit helps put scarce test CPU to better use.

3 thoughts on “Infrastructure load for November 2013

  1. I wonder if there is a correlation between mozilla-inbound pushes declining and try pushes increasing since June 2013. Maybe developers are testing their code on try instead of blindly landing on mozilla-inbound. 🙂

    • hi Chris;

      Good question, but I dont think so. Looking back over the years, Try Server usage is fairly consistently ~50% of our overall load. However, I do think that adding other sheriff-moderated integration branches (specifically b2g-inbound, fx-team) have played a big part in moving load away from mozilla-inbound. We’re seeing mozilla-inbound load reduce as developers switch instead to landing on b2g-inbound or fx-team… As evidence, I note that the combined load of the 3 different integration branches remains fairly consistently ~33% of our overall load.

      Good question though – thanks for asking.

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