GitWaterFlow: a successful branching model and tooling, for achieving continuous delivery with multiple version branches

Collaborative software development presents organizations with a near-constant flow of day-to-day challenges, and there is no available off-the-shelf solution that covers all needs. This paper provides insight into the hurdles that Scality's Engineering team faced in developing and extending a sophisticated storage solution, while coping with ever-growing development teams, challenging - and regularly shifting - business requirements, and non-trivial new feature development. The authors present a novel combination of a Git-based Version Control and Branching model with a set of innovative tools dubbed GitWaterFlow to cope with the issues encountered, including the need to both support old product versions and to provide time-critical delivery of bug fixes. In the spirit of Continuous Delivery, Scality Release Engineering aims to ensure high quality and stability, to present short and predictable release cycles, and to minimize development disruption. The team's experience with the GitWaterFlow model suggests that the approach has been effective in meeting these goals in the given setting, with room for unceasing fine-tuning and improvement of processes and tools.