Publish/subscribe systems have gained increasing interest in the past few years. There are many commercial products available today that rely on them directly. However, up to now there has been no discussion about pricing in such systems. We present a new strategyproof distributed algorithm that calculates the maximum subtree of the broker network and the costs arising for the clients. These payments sum up to the amount defined by the marginal cost mechanism and maximize the social surplus (i.e. the sum of the utilities minus the costs). It is taken into account that there may be multiple publishers serving one filter. An extended selfstabilized version copes with systems whose structure underlies a permanent change when publishers (dis-)appear and client utility changes. An adjustment is presented that considers different rates for subscriptions and therefore weakens the previous all-or-nothing scenario.
Andreas Tanner, Michael A. Jaeger