In large-scale distributed applications, a loosely-coupled event-based style of communication as in publish/subcribe systems eases the integration of autonomous, heterogeneous components. In a publish/subscribe system, content based routing - where routing is based on the content of the messages - is an alternative to address-based delivery. In this paper we compare the efficiency of two content-based routing algorithms: the flooding scheme and the more sophisticated identity-based routing scheme. Our analytical approach is based on continuous time Markov Chains and extends the steady state approach by Jaeger and Mühl  to systems with time-fluctuating parameters. We obtain explicit closed form solutions for the timedependent distribution of the number of active clients, taking into account the use of advertisements and roaming clients. The results allow us to investigate, for example, the switching point between optimality of flooding and identity-based routing.
|Name||Memorandum / Department of Applied Mathematics|
|Publisher||University of Twente, Department of Applied Mathematics|