Subscription-driven self-organization in content-based publish/subscribe

Recently many scalable and efficient solutions for rout-ing events in content-based systems realized through net-works of brokers have appeared in the literature. These so-lutions usually exhibit nice performance when subscribers with similar interest are physically close to each other (e.g. in the same LAN, domain or in the same geographical area) and connected to a broker which is also nearby. If these subscribers are dispersed on the Internet, the benefits of such routing strategies significantly decrease. In this pa-per we propose a novel approach for enhancing content-based routing performance through a self-organizing al-gorithm executed by the brokers whose aim is to logically place close (in terms of TCP hops) brokers that manage sub-scribers with similar interests. Metrics for measuring simi-larity of interests are discussed and a self-organizing algo-rithm is presented along with a performance analysis. 1