The role of models@run.time in supporting on-the-fly interoperability

Abstract

Models at runtime can be defined as abstract representations of a system, including its structure and behaviour, which exist in tandem with the given system during the actual execution time of that system. Furthermore, these models should be causally connected to the system being modelled, offering a reflective capability. Significant advances have been made in recent years in applying this concept, most notably in adaptive systems. In this paper we argue that a similar approach can also be used to support the dynamic generation of software artefacts at execution time. An important area where this is relevant is the generation of software mediators to tackle the crucial problem of interoperability in distributed systems. We refer to this approach as emergent middleware, representing a fundamentally new approach to resolving interoperability problems in the complex distributed systems of today. In this context, the runtime models are used to capture meta-information about the underlying networked systems that need to interoperate, including their interfaces and additional knowledge about their associated behaviour. This is supplemented by ontological information to enable semantic reasoning. This paper focuses on this novel use of models at runtime, examining in detail the nature of such runtime models coupled with consideration of the supportive algorithms and tools that extract this knowledge and use it to synthesise the appropriate emergent middleware.

A survey of autonomic computing methods in digital service ecosystems

“…• requirements reflection [81][82][83][84] • architectural styles for runtime adaptation [85,86] • digital evolution of behavioral models for autonomic systems [87][88][89][90][91] • evolutionary computation for DASs [92,93].…”

“…In [81][82][83][84], the authors following a top-down approach introduce a method for requirements reflection, which means making requirements available as runtime objects. Requirements reflection is important as future software systems will be self-managing and these systems need to adapt continuously to changing environmental conditions.…”

“…Several research challenges on requirements engineering of self-adaptive systems have been identified, such as dealing with uncertainty, runtime representation of requirements, evolution of the requirements model and synchronization with the architecture, and dynamic generation of software [81][82][83][84]. In order to deal with uncertainty, they use and extend goal-oriented requirements modeling (contextawareness support) with the RELAX language [99,100], which has been developed to support modeling and reasoning about uncertainty in design time and runtime models.…”

“…In [84], their method has been applied to synthesize emergent middleware to achieve interoperability in the context of the CONNECT project [102]. In emergent middleware, mediators are synthesized from runtime models, which provide support to reason about interoperability issues.…”

“…Runtime models provide reflective capability as they are casually connected to the system being modeled. They can be utilized for two purposes: (1) supporting reasoning about uncertainty and leveraging self-adaptation and (2) supporting the generation of software artifacts themselves, using model-driven engineering at execution time [84]. Both runtime adaptation and evolution are necessary to address the frequent changes imposed by DSEs.…”