Dynamic coordination architecture through the use of reflection

Abstract

In recent years, the research on Dynamic Software Architecture has received an increasing interest. The field is shifting from the description of "static" hierarchical interaction structures to the specification of open, dynamic environments: a capability that has been present in Coordination Models and Languages from the start. In this report Coordination and Dynamic Architectural Description Languages are considered as a whole, and their degrees of dynamism are studied. A taxonomy of existing approaches to the description of dynamic structures (architectures) is presented, stating their different capabilities and limitations. The use of concepts from the field of Computational Reflection (which enable the building of self-modifying systems) is suggested as a way to unify and extend all those approaches. These concepts are joined in a general framework named MARMOL, where meta-levels are made explicit. Architectural interaction is specified by the definition of meta-level connectors, which provide more dynamic and compositional capabilities. To show how this can be used in a language, an ADL named PiLar is briefly sketched, and a very simple example is described, to provide a first glimpse of its dynamic capabilities.

A survey of self-management in dynamic software architecture specifications

“…A variety of process algebras exist including the Calculus of Communicating Systems (CCS), Communicating Sequential Processes (CSP), and the π-calculus. We consider four process algebra approaches in this paper: Dynamic Wright [2], Darwin [15], LEDA [5], and PiLar [7].…”

An Architecture-Centric Approach for Information System Architecture Modeling, Enactement and Evolution

“…Few ADLs support dynamic architecture representation: Darwin (Magee et al, 1995), Dynamic Wright (Allen et al, 1998), -Space (Chaudet & Oquendo, 2000), C2SADEL (Medvidovic et al, 1999;, Piccola (Nierstrasz & Achermann, 2000), Pilar (Cuesta et al, 2005), ArchWare -ADL Oquendo 2004), ArchWare C&C-ADL . Most of them are not suitable to support unplanned dynamic architecture evolution as they consider different representations for the concrete and abstract levels, and use reflection mechanisms to switch among these representations: a dynamic architecture is first defined at abstract level and is then reflected (1) into a dynamic evolvable concrete software-intensive system (Cazzola et al, 1999;Tisato et al, 2000) or (2) into another, evolved abstract representation (Cuesta et al, 2001;Cuesta et al, 2005). The link between the abstract level and the concrete one is not maintained, leading to a situation in which only anticipated modifications can be supported dynamically.…”

The architecture of a dynamically updatable, component-based system

“…In [6] three levels of dynamism are introduced in ADLs: 1. Interactive dynamism (allows changing data only in fixed connections between fixed components), 2.…”

“…A model supporting dynamism in ADLs is represented by MARMOL (Meta ARchitectural MOdeL) [6]. MARMOL uses a language called Pilar, which allows reifying (creating links with meta-components) base components (called avatars) by their meta-components.…”

“…Our updatable, distributed system is inspired by MARMOL [6] and Olan [2]. Olan encapsules legacy software and communication in classes.…”