On Designing Self-Adaptive Software Systems

Ante condiciones cambiantes del entorno, los sistemas autoadaptativos pueden modificarse a sí mismos para controlar la satisfacción de sus requerimientos en tiempo de ejecución. Durante el siglo pasado los sistemas de retroalimentación fueron importantes modelos para controlar el comportamiento dinámico de sistemas mecánicos, eléctricos, de fluidos y químicos, en sus respectivos campos de la ingeniería. Más recientemente fueron adoptados para diseñar software autoadaptativo. No obstante, lograr mapeos coherentes y explícitos consistentemente entre las arquitecturas de software adaptativo y los elementos de sistemas de retroalimentación es aún un reto abierto. Este artículo, sobre un modelo de referencia propuesto con ese propósito, discute aspectos clave del diseño de software autoadaptativo, en que los elementos de sistemas de retroalimentación se definen explícitamente como componentes de primer nivel en su arquitectura. Adicionalmente, ilustra la aplicación de este modelo de referencia a un ejemplo real de software adaptativo. El artículo ofrece a los ingenieros de software un punto de referencia para iniciar el diseño de software autoadaptativo.Self-adaptive systems modify themselves at run-time in order to control the satisfaction of their requirements under changing environmental conditions. Over the past century, feedback-loops have been used as important models for controlling dynamic behavior of mechanical, electrical, fluid and chemical systems in the corresponding fields of engineering. More recently, they also have been adopted for engineering self-adaptive software systems. However, obtaining sound and explicit mappings consistently between adaptive software architectures and feedback loop elements is still an open challenge. This paper, recalling a reference model proposed previously with that goal, discuss key aspects on the design of adaptive software where feedback loop elements are explicitly defined as first-class components in its software architecture. It complements this discussion with an illustration of the process to use this reference model by applying it to a plausible adaptive software example. This paper aims at providing a reference starting point to support software engineers in the process of designing self-adaptive software systems

Software engineering for self-adaptive systems:research challenges in the provision of assurances

The important concern for modern software systems is to become more cost-effective, while being versatile, flexible, resilient, dependable, energy-efficient, customisable, configurable and self-optimising when reacting to run-time changes that may occur within the system itself, its environment or requirements. One of the most promising approaches to achieving such properties is to equip software systems with self-managing capabilities using self-adaptation mechanisms. Despite recent advances in this area, one key aspect of self-adaptive systems that remains to be tackled in depth is the provision of assurances, i.e., the collection, analysis and synthesis of evidence that the system satisfies its stated functional and non-functional requirements during its operation in the presence of self-adaptation. The provision of assurances for self-adaptive systems is challenging since run-time changes introduce a high degree of uncertainty. This paper on research challenges complements previous roadmap papers on software engineering for self-adaptive systems covering a different set of topics, which are related to assurances, namely, perpetual assurances, composition and decomposition of assurances, and assurances obtained from control theory. This research challenges paper is one of the many results of the Dagstuhl Seminar 13511 on Software Engineering for Self-Adaptive Systems: Assurances which took place in December 2013

C to Java Migration Experiences

With the growing popularity of the Java programming language for both client and server side applications in network-centric computing, there is a rising need for programming libraries that can be easily integrated into Java programs. In a previous paper, we surveyed current strategies for integrating C source code into Java programs, pointed out their weaknesses and presented goals for an improved migration approach. In this paper, we present the Ephedra approach to software migration and report on the results of three case studies transliterating C source code to Java using the Ephedra environment