Abstract. Distributed event routing has emerged as a key technology for achieving scalable information dissemination. In particular it has been used as preferential communication backbone within publish/subscribe communication system. Its aim is to reduce the network and computational overhead per event diffusion to a set (possibly large) of interested recipients. This paper introduces an unifying framework, namely a publish/subscribe architecture, that points out the functional decomposition between event-based routing layer, the overlay infrastructure layer and the network protocols layer. Hence the paper, firstly, surveys current algorithms for event based routing and possible overlay infrastructures in wired and mobile systems and, secondly, it discusses how and when single solutions at each level can be combined in the publish/subscribe architecture. Finally the paper positions existing publish/subscribe systems within the proposed architecture. 1

Abstract. Software product line engineering provides a systematic approach for the reuse of software assets in the production of similar software systems. For such it employs different variability modeling and realization approaches in the development of common assets that are extended and configured with different features. The result is usually generalized and complex implementations that may hide important dependencies and design decisions. Therefore, whenever software engineers need to extend the software product line assets, there may be dependencies in the code that, if not made explicit and adequately managed, can lead to feature interference. Feature interference happens when a combined set of features that extend a shared piece of code fail to behave as expected. Our experience in the development of YANCEES, a highly extensible and configurable publish/subscribe infrastructure product line, shows that the main sources of feature interference in this domain are the inadequate documentation and management of software dependencies. In this paper, we discuss those issues in detail, presenting the strategies adopted to manage them. Our approach employs a contextual plug-in framework that, through the explicit annotation and management of dependencies in the software product line assets, better supports software engineers in their extension and configuration.

Content-based publish/subscribe is a powerful data dissemination paradigm that offers both scalability and flexibility. However, its nature of high expressiveness makes it difficult to analyze or predict the behavior of the system such as event delivery probability and end-to-end delivery delay, especially when deployed over unreliable, best-effort public networks. This paper proposes the analytical model that abstracts expressiveness nature of content-based publish/subscribe, along with uncertainty of underlying networks, in order to predict quality of service in terms of delivery probability and timeliness based on partial, imprecise statistical attributes of each component in the system. Furthermore, the paper leverages the proposed prediction algorithm to implements heuristic-based subscriber admission control algorithms to maximize system utility when the system cannot support all subscribers. The evaluation results yields good prediction accuracy and admission rates. I.

Content-based Publish/subscribe systems (CBPS) is a simple yet powerful communication paradigm. Its content-centric nature is suitable for a wide spectrum of today’s content-centric applications such as stock market quote exchange, remote monitoring and surveillance, RSS news feed, and online gaming. As the trend shows that the amount of information along with its producers be-come astonishingly increasing everyday, a publish/subscribe system seems to be one of only a few viable choices that could govern the next-generation world of communication. However, the content-centric nature of a publish/subscribe system also poses difficulty in analyzing or assessing its performance. Moreover, the complexity increases when deploying a publish/subscribe system on top of best-effort, unreliable wide-area networks. Such uncertainty and complexity become a hindrance to apply content-based publish/subscribe systems to delay-sensitive applications that require reliable/timely event delivery and tight resource control such as soft real-time systems or cyber-physical systems. The need to solve such problem calls for a good analytical model that could capture both expressiveness and uncertainty nature of distributed CBPS systems yet predict the system behavior accurately.

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