XML processing issues have often been cited as a major reason for limited usage of XML in high-performance systems. This paper presents a case study of a large XML-based performance-driven web application based on a production deployment at a financial services firm. It introduces the concept of a 4-tier architecture, also referred to as the XML tier. In addition to the web servers, application servers and database servers, the XML tier, powered by hardware XML appliances, decouples XML Processing from the application server and database infrastructure.

This use case demonstrates that using XML in web applications can actually result in a scalable and cost-efficient architecture that enabled the financial institution to meet its performance and business requirements as the application and the number of dependent users rapidly increased.

These advantages are made possible by decoupling XML processing through integrated hardware XML appliances designed to process XML efficiently. In this particular case, such deployment has resulted in a tenfold throughput increase with 90% cost savings over scaling the general-purpose server infrastructure. This resulted in over $5 million saved in less than six months.