An Infrastructure for Adaptable Middleware

Abstract

Abstract. Today's software systems have to deal with an increasing diversity and complexity of execution environments. Next generation applications will have to deal with the unknown, with execution conditions which can not be predicted at the time they are written: they must be adaptable. In this paper, we present our current answer to this problem, in the form of an infrastructure for adaptable middleware. This infrastructure distinguishes functional components from non-functional services and enables dynamic reconfiguration of the associations between them. These associations are controlled by an adaptation engine which monitors both the execution environment and the application, and adapts the associations according to adaptation policies.

Modelling adaptive services for distributed systems

“…There is a large amount of work devoted to the development of frameworks and middleware infrastructures to facilitate the implementation of adaptive systems [9,7,18,6,3,5]. There are architecture-based adaptation frameworks such as Rainbow [7], whose main goal is to be general purpose, applicable to a wide variety of systems with dierent architecture styles.…”

Techniques for Dynamic Adaptation of Mobile Services

“…Many policies will also contain some restrictions or guards confining the rule action to appropriate occasions. This event-conditionaction (ECA) format is standard for rule-based adaptation systems [4,5,6,8,9,16,19,33,34,35,36,40], where an adaptation management system is responsible for monitoring these events, evaluating the conditions and initiating the management action on the targeted managed object. In a policy-based dynamic adaptation system it should be possible to edit the rule set and have them re-interpreted to support the dynamic addition of new rules or changes in policy.…”

“…RAM (Reflection for Adaptable Mobility) [4,9] from École des Mines de Nantes, takes the approach of completely separating functional and non-functional aspects of an application in a manner related to aspect oriented programming (AOP). Using this separation of concerns approach, only the core application functionality is inserted into the application code, with all middleware services represented as non-functional concerns.…”

“…Container meta objects wrap each application, and supports the compositions of other meta object which implement these non-functional concerns. The wrapping of application objects with Containers occurs at either load-time using Javassist [7] in [4] or at compile-time using AspectJ [42] in [9]. These meta objects provide the middleware services by selecting appropriate RoleProvider objects for each service, i.e., the meta objects that provide the actual implementations of the services.…”

Chisel: a policy-driven, context-aware, dynamic adaptation framework

“…RAM [9] from École des Mines de Nantes, France take the approach of completely separating functional and nonfunctional aspects of an application in a manner related to Aspect Oriented Programming. Using this separation of concerns approach, only the core application functionality is inserted into the application code, with all middleware services represented as non-functional concerns.…”