Scalability and extensibility in client-independent server architectures

Abstract

In this research we are inspecting the client-independent server software architectures and their two most important quality aspects, scalability and extensibility. By client-independent server software architecture we mean the ability of the server architecture to treat the requester of its services in a similar manner. Scalability implies the ability for the architecture to grow and accommodate increasing numbers of users, applications, and systems (Riverton 2004). Extensibility is the development-oriented quality factor representing the ease with which something can be enhanced to meet future goals and significantly changing requirements (OPFRO 2005). The aim of this research is to find out what are the requirements that the scalability and extensibility set for the design of the client-independent server software architectures. Especially we are focusing on how these requirements may be fulfilled by presenting general solutions on the problem area. In this research we are focusing only on scalability and extensibility on the client-independent server software architectures leaving out any other quality attributes or requirements. Nowadays systems are more often based on the client/server architecture and the client may be besides traditional workstation any kind of hardware from servers to personal digital assistants (PDA s) and mobile phones, based on many different technologies. Each of these terminals has their own requirements and interfaces towards servers services. This sets specific requirements on the implementation of server architectures, to be able to be modified on clients needs with as low resources as possible Also these architectures should be implemented in a manner that they could be used in a similar

kind of situation in the future. The handling of the subject is based on examples, which have been recognised as industrial best practices. To provide these examples many different approaches in the literature have been studied. After this the presented examples are combined to give a sample solution to issues presented. The outcome of this research is the recognised problems in the area and a sample solution to overcome these issues. The produced sample solution proves that with well defined server software architecture design the server may be implemented to be client-independent and at the same time the server may provide good scalability and extensibility.