The Buildbot consists of a single buildmaster and one or more
buildslaves, connected in a star topology. The buildmaster
makes all decisions about what, when, and how to build. It sends
commands to be run on the build slaves, which simply execute the
commands and return the results. (certain steps involve more local
decision making, where the overhead of sending a lot of commands back
and forth would be inappropriate, but in general the buildmaster is
responsible for everything).
The buildmaster is usually fed Changes by some sort of version control
system (see Change Sources), which may cause builds to be run. As the
builds are performed, various status messages are produced, which are then sent
to any registered Status Targets (see Status Targets).
The buildmaster is configured and maintained by the “buildmaster admin”, who is generally the project team member responsible for build process issues. Each buildslave is maintained by a “buildslave admin”, who do not need to be quite as involved. Generally slaves are run by anyone who has an interest in seeing the project work well on their favorite platform.