Data-driven Workflows for Microservices

TL;DR

This paper enhances the Jolie microservices programming language by adding data type choices, enabling data-driven workflows and revealing common communication patterns for microservice system design.

Contribution

It introduces support for data type choices in Jolie, facilitating a shift from process-driven to data-driven microservice architectures.

Findings

Extended Jolie with data type choices.

Impact on typical microservice scenarios.

Preliminary design patterns for communication.

Abstract

Microservices is an architectural style inspired by service-oriented computing that has recently started gaining popularity. Jolie is a programming language based on the microservices paradigm: the main building block of Jolie systems are services, in contrast to, e.g., functions or objects. The primitives offered by the Jolie language elicit many of the recurring patterns found in microservices, like load balancers and structured processes. However, Jolie still lacks some useful constructs for dealing with message types and data manipulation that are present in service-oriented computing. In this paper, we focus on the possibility of expressing choices at the level of data types, a feature well represented in standards for Web Services, e.g., WSDL. We extend Jolie to support such type choices and show the impact of our implementation on some of the typical scenarios found in microservice systems. This shows how computation can move from a process-driven to a data-driven approach, and leads to the preliminary identification of recurring communication patterns that can be shaped as design patterns.