Over the last decade a wide range of publish/subscribe (pub/ sub) systems have come out of the research community. However, there is little consensus on a common pub/sub API, which would facilitate innovation, encourage application building, and simplify the evaluation of existing prototypes. Industry pub/sub standards tend to be overly complex, technology-centric, and hard to extend, thus limiting their applicability in research systems. In this paper we propose a common API for pub/sub that is tailored towards research requirements. The API supports three levels of compliance (with optional extensions): the lowest level specifies abstract operations without prescribing an implementation or data model; medium compliance describes interactions using a light-weight XML-RPC mechanism; finally, the highest level of compliance enforces an XML-RPC data model, enabling systems to understand each other's event and subscription semantics. We show that, by following this flexible approach...
Peter R. Pietzuch, David M. Eyers, Samuel Kounev,