Programming of distributed systems1 (

PROGRAMMING OF DISTRIBUTED SYSTEMS

José Rui Peixoto Escola Superior de Tecnologia e Gestão de Viana do Castelo Mestrado em Engenharia de Software – Programação de Sistemas Distribuídos 2012

SUMMARY

With the popularization of Internet usage, of computer networking and, more recently, mobile computing, the need for distributed systems arises, so that there can be a boost in the performance and potential of each one of the system components and to optimize procedures through resource sharing. When I mention Distributed Systems, I specifically mean an Information System in which the several components find themselves geographically separated, but all the actions are coordinated and the communication between systems is something continually occurring.
1 INTRODUCTION Computer networks and above all the Internet changed deeply the paradigm of computing. That we cannot deny. Nowadays, we can see a constant and profound revolution towards the evolution of mobile computing and because of this, significant changes are happening in the Software industry. Still in the matter of existing connections, we have private networks such as the ones in companies, state institutions, banks and among others. This way, an increasing motivation for resource sharing arises, propelled by the emergence of new possibilities.

Besides the evolutional factors above mentioned, there is still a major factor which is the geographical distance between the different resources that are shared, such as software and hardware components. We have today, and as an example, a bank in New York that needs to access information stored in a disk that is physically located in Brussels. It is about this kind of resource sharing that my approach in this article is focused on. It is in this basis that the programming paradigm of distributed systems appears, concept that can be summarized by its own definition. Distributed systems are thus described as systems “[...] in which the different hardware and