A Systematic Approach for Configuring Web-Based Information Systems

摘要

Enterprise information systems consist of interrelated Intranet and Internet-based applications, thus the Web platform serves well as the middleware for their development. Using a Web Browser, it is possible to download the user interface of any web-based application from anywhere around the world, providing transparency in application implementation. A web-based information system can be described as a set of web-based applications and the underlying infrastructure (both Intranet and Internet). Although most information systems built to support current technological treads are based on this architecture, they often fail to provide the desired performance. A potential cause is that, configuration issues, although interrelated, are solved in isolation. As the underlying network topology strongly influences application configuration, the relationship between the resource allocation policy and network architecture should be explored. We, thus, argue that a systematic approach for the quantitative analysis, effective configuration and detailed performance evaluation of web-based information systems is required. Four discrete stages are identified. The consistent representation of system specifications throughout all configuration stages facilitates the exploration of their dependencies even if these aren't obvious. For this purpose, we propose a common meta-model, incorporating specific characteristics of web-based systems. UML-like notation was adopted for system specification representation. Two are the main advantages of the proposed meta-model: extendibility, facilitating the description of applications at different levels of abstraction, and consistency, ensuring the accurate estimation of the Quality of Service parameters imposed to the underlying network by the described applications. A case study where the proposed approach was used for configuring a complex web-based system and the experience obtained are also discussed.