[Buildbot-devel] How does build request merging work?

[David Coppit]

I'm trying to understand the default build merging behavior. It seems to me that sourcestamps, buildsets, and buildrequests are created as soon as the tree stable timer expires (and as long as the branch/repository filtering is satisfied). Then later build requests are merged, as well as the sourcestamps and maybe the buildsets as well?

Let's say I have 20 schedulers that are generating a bunch of build requests at a rate faster than the machines can build. Will Buildbot merge pending buildrequests such that at most there is one one build request for recent builds? i.e. will it throttle the creation of build requests, instead creating fewer builds with larger lists of changes, as needed?

If a change comes in, then a try build, then another change, is Buildbot smart enough to merge the first and third build request?

Basically I'm looking for the build merging to adapt to the availability of machines, rather than queueing build requests.