Mozilla has been quite involved in recent buildbot development, in particular, helping to make it scale across multiple machines. More on this in another post! Once deployed, these changes will give us the ability to give real time access to various information about our build queue: the list of jobs waiting to start, and which jobs are in progress. This should help other tools like Tinderboxpushlog show more accurate information. One limitation of the upstream work so far is that it only captures a very coarse level of detail about builds: start/end time, and result code is pretty much it. No further detail about the build is captured, like which slave it executed on, what properties it generated (which could include useful information like the URL to the generated binaries), etc. We've also been exporting a json dump of our build status for many months now. It's been useful for some analysis, but it also has limitations: the data is always at least 5 minutes old by the time you look, and in-progress builds are not represented at all. We're starting to look at ways of exporting all this detail in a way that's useful to more people. You want to get notified when your try builds are done? You want to look at which test suites are taking the most time? You want to determine how our build times change over time? You want to find out what the last all-green revision was on trunk? We want to make this data available, so anybody can write these tools.
Just how big is that firehose?I think we have one of the largest buildbot setups out there and we generate a non-trivial amount of data:
- 6-10 buildbot master processes generating updates, on different machines in 2 or 3 data centers
- around 130 jobs per hour composed of 4,773 individual steps total per hour. That works out to about 1.4 updates per second that are generated