Self-Adaptive Systems: A Middleware Managed Approach

Abstract

Abstract. Recent works on self-adaptivity use a middleware-based approach where the adaptation mechanisms and meta-level information are separated and externalized from the application code. Current solutions generally target individual life-cycle phases of an application in isolation, preventing easy integration of design-time and run-time adaptability. Integration is needed in order to support the introduction of new adaptive behavior during run-time. Self-adapting systems therefore need to support both planning, instantiation and maintenance of applications throughout their life-time.In this paper we propose middleware managed adaptation, in which services are specified by their behavior, and planned, instantiated and maintained by middleware services in such a way that the behavioral requirements are satisfied throughout the service life-time. Central to this approach is mirror-based reflection, which supports introspection and intercession on an application, or any service, through all the phases of its life-cycle, including pre-runtime. The mirror of a service may contain information about its implementation, including the developer's knowledge about how this implementation will perform in different contexts. By making this knowledge available to the middleware, we facilitate the implementation of a wide range of self-adaptive behaviors.

Dynamic Adaptation of Fragment-Based and Context-Aware Business Processes

“…As mentioned in [12], in order to support services whose adaptive behavior can evolve over time, there is a need for higher level adaptation policies that are architecture independent. In this respect, Kramer and Magee propose in [14] a three-layer reference architecture for dealing with self-managed or self-* systems.…”

An Agent-Based Middleware for Adaptive Systems

“…Self-adaptive systems are able to adapt to changing user needs and resource requirements at run-time, according to [4]. Systems adapting themselves toward changing environment providing dependability and robustness without human intervention are called Self-adaptive systems in [5].…”

Evolving self-adaptive services using planning-based reflective middleware

“…Central to this middleware is mirror-based service reflection, which supports introspection and intercession on a service through all the phases of its life-cycle, including pre-runtime [7]. Each service is represented by a service mirror, which is an object reflecting the service behavior and implementation.…”