An Exploration of Cross-Patch Collaborations via Patch Linkage in OpenStack

TL;DR

This paper investigates how patch linkages in OpenStack facilitate cross-patch collaboration, revealing that such linkages, though less frequent, have a higher likelihood of leading to collaborative contributions that impact review outcomes.

Contribution

It is the first empirical study exploring the role of patch linkages in fostering cross-patch collaboration within large open-source ecosystems like OpenStack.

Findings

Patch linkages are less common but more likely to lead to collaboration.

Collaborative contributions can influence review outcomes and improve patches.

Patch linkage-based collaboration presents new opportunities for enhancing code review processes.

Abstract

Contemporary development projects benefit from code review as it improves the quality of a project. Large ecosystems of inter-dependent projects like OpenStack generate a large number of reviews, which poses new challenges for collaboration (improving patches, fixing defects). Review tools allow developers to link between patches, to indicate patch dependency, competing solutions, or provide broader context. We hypothesize that such patch linkage may also simulate cross-collaboration. With a case study of OpenStack, we take a first step to explore collaborations that occur after a patch linkage was posted between two patches (i.e., cross-patch collaboration). Our empirical results show that although patch linkage that requests collaboration is relatively less prevalent, the probability of collaboration is relatively higher. Interestingly, the results also show that collaborative contributions via patch linkage are non-trivial, i.e, contributions can affect the review outcome (such as voting) or even improve the patch (i.e., revising). This work opens up future directions to understand barriers and opportunities related to this new kind of collaboration, that assists with code review and development tasks in large ecosystems.