Pubsub: An Efficient Publish/Subscribe System

PUBSUB is a versatile, efficient, and scalable content-based publish/subscribe system. This paper describes the architecture of PUBSUB together with some of its current capabilities. A version of PUBSUB optimized for event processing was benchmarked against the publish/subscribe systems BE-Tree and Siena, which also are optimized for event processing. Although the run time performance of both BE-Tree and PUBSUB is orders of magnitude better than that of Siena, BE-Tree is able to handle only a restricted class of predicates while PUBSUB can handle most predicate types handled by Siena. On our tests, the speedup of the fastest version of PUBSUB relative to Siena ranged from a low of 18 to a high of 1,703 and averaged 185. The speedup range relative to BE-Tree was up to 9.81 and averaged 2.37. Siena´s memory requirements are about a fourth of those of BE-Tree and PUBSUB. The memory required by the most memory efficient of PUBSUB ´s data structures was between 4 and 16 percent less that required by BE-Tree. With respect to data structure initialization, the three systems took a comparable amount of time on some data sets while on some PUBSUB could be initialized in 1/7th time required to initialize Siena and 1/14th that to initialize BE-Tree. PUBSUB achieves its high performance from the use of very efficient data structures and event matching algorithms.