A contract-based approach to describe and deploy non-functional adaptations in software architectures

Abstract

This paper presents a comprehensive approach to describe, deploy and adapt component-based applications having dynamic non-functional requirements. The approach is centered on high-level contracts associated to architectural descriptions, which allow the non-functional requirements to be handled separately during the system design process. This helps to achieve separation of concerns facilitating the reuse of modules that implement the application in other systems. Besides specifying non-functional requirements, contracts are used at runtime to guide configuration adaptations required to enforce these requirements. The infrastructure required to manage the contracts follows an architectural pattern, which can be directly mapped to specific components included in a supporting reflective middleware. This allows designers to write a contract and to follow standard recipes to insert the extra code required to its enforcement in the supporting middleware.

An Adaptive Control Model for Non-functional Feature Interactions

“…In this way we can make non-functional properties and their feature-interactions explicit. Other work such as [17] and [19] focuses on modularity regarding the specification of non-functional properties, but do not consider feature interactions on this level.…”

Non‐functional information transmission patterns for distributed real‐time Java

“…Some pieces of work deal with contract‐based approaches for distributed real‐time Java. Loques et al 39 present a contract‐based approach to describe and deploy non‐functional adaptations in software architectures. One of the multiple scenarios they considered is the use of RT‐RMI as a kind of connector.…”

An integration experience of a software architecture and a monitoring infrastructure to deploy applications with non‐functional requirements in computing grids

“…One example of an infrastructure that supports the Contract concept is the CR‐RIO (Contract Reflexive‐Reconfigurable Interconnected Objects), which integrates the software architecture paradigm, centered on an ADL, to reflection mechanisms and dynamic adaptation capabilities 2, 3. It includes a Configurator , a reflective element that provides services to instantiate, execute and reconfigure distributed applications, whose architectures are described with the CBabel ADL.…”

“…Our implementation employs a simplified version of the CR‐RIO contracts 2. Each contract can specify two profiles, which describe the service quality level.…”

“…We used Software Architecture concepts and an Architecture Description Language (ADL), along with the support of a QoS‐aware infrastructure to build dynamic reconfigurable distributed applications, such as video on demand (VoD). The application's components are selected according to the contract specified using the ADL 2–4. Interesting problems, such as reconfiguration consistency 5 and stability 6 were tackled.…”