On April 10^th, Marco Peressotti gave a talk at the 33^rd ACM/SIGAPP Symposium On Applied Computing (SAC’18) about the paper “Communications in Choreographies, Revisited”. On April 11^th, Janine Weber presented a poster at SAC’18 about the paper “From the decorator pattern to circuit breakers in microservices”.

In “Communications in Choreographies, Revisited”, Luís Cruz-Filipe, Fabrizio Montesi, and Marco Peressotti propose a model of choreographic programming equipped with a primitive for grouped interactions that subsumes several communication patterns commonly used by real-world systems like multicast, scatter-gather, and atomic exchanges. Intuitively, grouped interactions can be thought of as being carried out as one single interaction. In practice, they are implemented by processes that carry them out in a concurrent fashion. After formalising the intuitive semantics of grouped interactions, the authors prove that choreographic programs and their implementations are correct and deadlock-free by construction.

In “From the decorator pattern to circuit breakers in microservices”, Fabrizio Montesi and Janine Weber analyse different deployment setups for circuit breaker, a design pattern for preventing cascading failures by guarding calls towards a target service. Then, they define a unifying implementation strategy in the setting of microservices, by using the Jolie programming language. Their implementation captures all setups with a single program, by interpreting a circuit breaker as a decorator that is generic on the interface of its target service.