WEB APPLICATION'S RELIABILITY IMPROVEMENT THROUGH ARCHITECTURAL PATTERNS

Scalability and availability are two highly desirable attributes pertaining to reliability of a web application that renders state-of-the-art services to online users. In simple words scalability is the ability to grow, the ability to serve increased number of requests or clients. Building a scalable application with round the clock availability is a challenging problem in the light of ever increasing population of potential users. Dramatic increase in users to web application causes bursts of requests that put the application to acid test. On the other hand web application availability represents the degree of operational continuity. High availability and unlimited scalability are the two indispensable quality attributes a web application in the real word. These features bestow rich user experience as far as operational continuity and ability to handle growing workload are concerned. By taking server side measures it is possible to achieve these two desirable features. However, there is possibility to have architectural pattern along with underlying design patterns to promote these quality features of web application. In this paper we enhance our architectural pattern eXtensible Web Application Development Framework (XWADF) that can leverage the quality of web application design as it result in highly scalable with high availability. As the application is designed in XWADF framework it promotes scalability assuming server side supports in terms of resources. The application also ensures availability as the design supports maintenance without letting the application down. The empirical results revealed that our architectural approach increases reliability of web applications significantly in terms of availability and scalabilit