Learn More
Subscription adaptations are becoming increasingly important across many content-based publish/subscribe (CPS) applications. In algorithmic high frequency trading, for instance, stock price thresholds that are of interest to a trader change rapidly, and gains directly hinge on the reaction time to relevant fluctuations. The common solution to adapt a(More)
Event-based programming is an appealing paradigm for developing pervasive systems since events enable the decoupling of interacting components. Unfortunately, many event-based languages and systems have hardwired notions of physical or logical time and space. This limits their adaptability and target deployment environments, as pervasive systems rely on(More)
Content-based publish/subscribe (CPS) is an appealing abstraction for building scalable distributed systems, e.g., message boards, intrusion detectors, or algorithmic stock trading platforms. Recently, CPS extensions have been proposed for location-based services like vehicular networks, mobile social networking, and so on. Although current CPS middleware(More)
To efficiently design deduplication, caching and other management mechanisms for virtual machine (VM) images in Infrastructure as a Service (IaaS) clouds, it is essential to understand the level and pattern of similarity among VM images in real world IaaS environments. This paper empirically analyzes the similarity within and between 525 VM images from a(More)
Adoption of hybrid clouds by enterprises has been hampered by the inability of current hybrid cloud infrastructures to provide scalable and efficient mechanisms (1) to ensure the trustworthiness and integrity of the software stack executing a hybrid application workload, or (2) to enforce governmental privacy, data jurisdiction and audit regulations by(More)
Many distributed applications rely on event correlation. Such applications, when not built as ad-hoc solutions, typically rely on centralized correlators or on broker overlay networks. Centralized correlators constitute performance bottlenecks and single points of failure; straightforwardly duplicating them can hamper performance and cause processes(More)