Concurrency Testing: A Journey from Research to Practice

Concurrency is fundamental for building scalable software systems. Despite the prevalence of such systems, testing them remains an uncomfortable problem for developers. Concurrency bugs are hard to find, reproduce and fix, and for most part, they get ignored in standard industry practices. To address this need, we have built and deployed an open-source tool called Coyote that uses the concept of Controlled concurrency testing (CCT) to explore the space of possible interleavings of a concurrent program looking for bugs. In this talk, I will describe the (rather long) research journey and the several turns that it took through a whole community of researchers, and finally inspired the Coyote tool in the way that it is designed today. Coyote has been downloaded around a million times and is used routinely for testing of Azure infrastructure services.