Some figures about PPA queues

I actively maintain a bunch of packages in a few PPAs, including some automated dailies. I often wonder how crowed the PPA builders are and what the best time of the day is to send updates.

This has a direct impact on when the resulting debs are available to users, especially with chained builds (where packages are stuck in DEPWAIT state for a while waiting for something else to complete). It is also important for me to keep those PPAs green, so I want to minimize the time between a FAILEDTOBUILD and when I can work on a fix.

I decided to monitor those builders for a few days, here is what I came up with:

As expected, i386 is the most crowed arch (it is doing the all-arch builds too) but in general, queues are quite empty, meaning almost instantaneous build-starts. This is good news indeed, I was not expecting that. Peaks seem to be absorbed pretty well too, kudos to the Launchpad guys for that!

This cumulative graph is also interesting:

Obviously, there's a good window where instant start is possible. That's 3am-1pm (CET, or 6pm-8am PDT, 12am-10pm EST). I found out that 7pm was the best practical time for me to push updates and fix failures in a timely manner, yet, it's also a rush hour for the builders (for which I'm partially responsible), so I may have to rethink my strategy.