Subscription tree pruning: A structure-independent routing optimization for general-purpose publish/subscribe systems.

摘要

A main challenge in distributed publish/subscribe systems is the efficientand scalable routing of incoming information (event messages). For largescalepublish/subscribe services, subscription forwarding has been established asa prevalent routing scheme. It reduces the network traffic for event routing dueto selectively forwarding event messages to relevant parts of the network only.To further improve event routing, publish/subscribe systems apply routing optimizations.So far, optimizations for general-purpose publish/subscribe systemsare still missing.In this paper, we present the architecture, realization, and evaluation of our prototypeof a large-scale publish/subscribe service applying a novel routing optimization,subscription tree pruning. We also show a comparison of five existingrouting optimizations in respect to six important characteristic parameters affectingthe suitability of these approaches in practice (including space usage, timeefficiency (throughput), and network load). This comparative analysis clearlydemonstrates the advantages of subscription pruning over other routing optimizations.In our practical experiments, we then investigate the behavior of our prototyperegarding all quantitatively measurable parameters from our previouslytheoretically analyzed ones. Our evaluation of subscription pruning in this paperis more extensive than previous analyses of any routing optimizations for publish/subscribe systems, which focus on selected parameters only.