Towards an Internet-Scale XML Dissemination Service

This chapter addresses several challenges in the context of incorporating the rich functionality of XML data dissemination in a highly scalable system. It presents the architectural design of Operator Network using YFilter for XML dissemination (ONYX), a system based on an overlay network. Also, it identifies the salient technical challenges in supporting XML filtering and transformation and proposes techniques for solving them. Publish/subscribe systems have demonstrated the ability to scale to large numbers of users and high data rates when providing content-based data dissemination services on the Internet. However, their services are limited by the data semantics and query expressiveness that they support. On the other hand, the recent work on selective dissemination of XML data has made significant progress in moving from XML filtering to the richer functionality of transformation for result customization, but generally ignores the challenges of deploying such XML-based services on an Internet scale.