The data-centricity of Web 2.0 workloads and its impact on server performance

Advances in network performance and browser technologies, coupled with the ubiquity of internet access and proliferation of users, have lead to the emergence of a new class of Web applications, called Web 2.0. Web 2.0 technologies enable easy collaboration and sharing by allowing users to contribute, modify, and aggregate content using applications like Wikis, Blogs, Social Networking communities, and Mashups. Web 2.0 applications also make heavy use of Ajax, which allows asynchronous communication between client and server, to provide a richer user experience. In this paper, we analyze the effect of these new features on the infrastructure that hosts these workloads. In particular, we focus on the data-centricity, inherent in many Web 2.0 applications, and study its impact on the persistence layer in an application server context. Our experimental results reveal some important performance characteristics; we show that frequent Ajax requests, and other requests arising from the participatory nature of Web 2.0, often retrieve and update persistent data. This can lead to frequent database accesses, lock contention, and reduced performance. We also show that problems in the persistence layer, arising from the data-intensive nature of Web 2.0 applications, can lead to poor scalability that can inhibit us from exploiting current and future multicore architectures.