A dynamic platform for runtime adaptation

Abstract

Abstract-We present a middleware platform for assembling pervasive applications that demand fault-tolerance and adaptivity in distributed, dynamic environments. Unlike typical adaptive middleware approaches, in which sophisticated component model semantics are embedded into an existing, underlying platform (e.g., CORBA, COM, EJB), we propose a platform that imposes minimal constraints for greater flexibility. Such a tradeoff is advantageous when the platform is targeted by automatic code generators that inherently enforce correctness by construction.Applications are written as simple, single-threaded programs that assemble and monitor a set of distributed components. The approach decomposes applications into two distinct layers: (1) a distributed network of interconnected modules performing computations, and (2) constructor logic that assembles that network via a simple block-diagram construction API. The constructor logic subsequently monitors the configured system via a stream of high-level events, such as notifications of resource availability or failures, and consequently provides a convenient, centralized location for reconfiguration and debugging. The component network is optimized for performance, while the construction API is optimized for ease of assembly.

Pervasive maps: Explore and interact with pervasive environments

“…As a result, it remains difficult for end-users to differentiate between similar resources based on a description, especially in complex environments with many embedded computing resources. Various other middleware systems have been proposed for building context-aware pervasive services [5], [15], [9]. This landscape of diverse technologies for creating and deploying pervasive services demands for a generic solution to discover and leverage them in useful ways.…”

PerViz: Painkillers for pervasive application debugging

“…To test our approach, PerViz targets applications built us ing our Planner [2] and Components platform [3]. However, the principles are general, and PerViz features APIs to enable integration with other systems.…”

“…To experiment with PerViz, we used our Goal-oriented ap plication Planner [2] combined with our Components system 2\0 [3] as the application middleware. Our middleware targets pervasive applications that naturally decompose into two parts: a planning process (or context manager) responsible for making high-level decisions (e.g., adaptation, resource allocation, or contextual decisions) during the life of the application, and a component-based implementation, on which the application executes.…”