Caching Dynamic Web Content: Designing and Analysing an Aspect-Oriented Solution
Caching dynamic web content is an effective approach to reduce Internet latency and server load. An ideal caching solution is one that can be added transparently by the developers and provides complete consistency of the cached documents, while minimizing false cache invalidations. In this paper, we design and implement AutoWebCache, a middleware system for adding caching of dynamic content transparently to J2EE server-side applications having a back-end database. For this purpose, we first present the principles involved in caching dynamic web content, including our logic to ensure consistency of the cached entries. Thereafter, we demonstrate the use of aspect-oriented (AOP) techniques to implement our system, showing how AOP provides modularity and transparency to the entire process. Further, we evaluate the effectiveness of AutoWebCache in reducing response times of applications, thereby improving throughput. We also analyze, the transparency of our system for a general application suite, considering issues such as dynamic web pages aggregating data from multiple sources, presence of insufficiently structured interfaces for exchanging information and the use of application semantics while caching. We use two standard J2EE web benchmark applications, RUBiS and TPC-W, to conduct our experiments and discuss the results obtained.