Providing quality of service in wide-area publish/subscribe systems: poster

In recent years, the industry has witnessed an increasing trend of exploiting the publish/subscribe paradigm for integrating and expanding enterprise application domains over large geographic areas. The quality of the publish/subscribe service plays a critical role in the overall system performance as perceived by the end users. In this work, we present an overlay-based publish/subscribe system, called Harmony, that can manage the end-to-end QoS in latency, throughput and availability, based on the application requirements. This is achieved through a holistic set of overlay routing mechanisms that actively exploit the diversity in the network paths and direct the traffic over links with high quality, based on the feedback from a distributed network monitoring component. Harmony also provides highly available services with minimal traffic overhead, through carefully establishing multiple paths and backup brokers. We have validated these capabilities in the context of a national airspace surveillance system, where a large volume of real-time aircraft tracking data from different sources is transported among various federal agencies located throughout the US continent.