A framework for distributed content-based web services notification in Grid systems

We describe a content-based distributed notification service for Publish/Subscribe communication that implements the WS-Notification (WSN) standards. The notification service is built on a messaging framework that supports an associative rendezvous messaging mechanism on a structured overlay of peer nodes. The entire system acts as a notification broker, so that notification publishers and subscribers outside the network can achieve loosely coupled communication through a decentralized, scalable service, by interacting with any of the broker peers. Self-optimizing mechanisms are built into the framework to reduce notification traffic within as well as from the peer network. We describe the framework and its performance and evaluate the effectiveness of the self-optimizing mechanisms.