CWI improves coordination technology to combine large internet services

 José Proença, PhD student from the Centrum Wiskunde & Informatica (CWI) in Amsterdam, developed new coordination techniques to combine large Internet services efficiently. Software components need to be coordinated to form a working system. This is, for example, important for cloud computing, where web services play a key role, and for the efficient use of multi-core architectures. On 11 May, Proença defended his PhD dissertation 'Synchronous Coordination of Distributed Components' at Leiden University. As part of his thesis, he created 'Dreams', a prototype open-source framework that can be used by software engineers to combine distributed services and components in a structured and easy-to-maintain manner.

A distributed system is divided into several subsystems each of which performs specific computations. Both of their resources and results are then coordinated by means of a coordination layer, written in a coordination language – a formal, mathematical computer language. For his research, Proença used Reo, a powerful coordination language introduced by the CWI research group Foundations of Software Engineering. Reo’s power comes from its expressiveness and modularity – larger systems are built by composing smaller systems. However, until now it was hard to run and execute large distributed systems. Proença showed that the complex operations described by Reo can be implemented in larger distributed systems, illustrating the usefulness of Reo models.

The both theoretical and practical work of Proença improves the execution of combined services in distributed systems in terms of size and speed. He accomplished three major contributions: The first achievement is the working implementation of Reo on large distributed systems, complementing the extensive theoretical work being developed for it. Secondly, his work supports decoupling and lightweight reconfiguration, which means that a system can be separated into smaller subsystems, executing independently, making adjustments to a running system inexpensive. Thirdly, his work outperforms previous attempts in speed and cost.

Supervisor was Prof. dr. F. Arbab (CWI and Leiden University); co-supervisors were dr. D. Clarke (Katholieke Universiteit Leuven, Belgium) and dr. E.P. de Vink (Eindhoven University of Technology and CWI). The PhD was financed by the Portuguese foundation Fundação para a Ciência e Tecnologia (FCT).


More information:

- website of the Reo project

- source code of Dreams

- homepage of José Proença