Event-driven Adaptation in COP

Context-Oriented Programming languages provide us with primitive constructs to adapt program behaviour depending on the evolution of their operational environment, namely the context. In previous work we proposed ML_CoDa, a context-oriented language with two-components: a declarative constituent for programming the context and a functional one for computing. This paper describes an extension of ML_CoDa to deal with adaptation to unpredictable context changes notified by asynchronous events.Comment: In Proceedings PLACES 2016, arXiv:1606.0540

A Context-Oriented Extension of F#

Context-Oriented programming languages provide us with primitive constructs to adapt program behaviour depending on the evolution of their operational environment, namely the context. In previous work we proposed ML_CoDa, a context-oriented language with two-components: a declarative constituent for programming the context and a functional one for computing. This paper describes the implementation of ML_CoDa as an extension of F#.Comment: In Proceedings FOCLASA 2015, arXiv:1512.0694

Leveraging Self-Adaptive Dynamic Software Architecture

Software systems are growing complex due to the technological innovations and integration of businesses. There is ever increasing need for changes in the software systems. However, incorporating changes is time consuming and costly. Self-adaptation is therefore is the desirable feature of any software that can have ability to adapt to changes without the need for manual reengineering and software update. To state it differently robust, self adaptive dynamic software architecture is the need of the hour. Unfortunately, the existing solutions available for self-adaptation need human intervention and have limitations. The architecture like Rainbow achieved self-adaptation. However, it needs to be improves in terms of quality of service analysis and mining knowledge and reusing it for making well informed decisions in choosing adaptation strategies. In this paper we proposed and implemented Enhanced Self-Adaptive Dynamic Software Architecture (ESADSA) which provides automatic self-adaptation based on the runtime requirements of the system. It decouples self-adaptation from target system with loosely coupled approach while preserves cohesion of the target system. We built a prototype application that runs in distributed environment for proof of concept. The empirical results reveal significance leap forward in improving dynamic self-adaptive software architecture

تحسين توافرية وأداء النظام الموزع بإعادة انتشار مكونات النظام

استخدمت النظم الموزعة كثيراً في الآونة الأخيرة كبديل عن النظم المركزية نظراً لأدائها الأفضل عندما يزداد حجم النظام أو تزيد الحاجة إلى موارد المعالجة. رغم ذلك لازالت تعاني تلك النظم من مشاكل ضعف التوافرية عند حدوث تغيير في البنية التحتية التي تعمل فوقها مما أدى إلى ظهور مفهوم إعادة انتشار مكونات النظام الموزع. في هذا البحث تم تقديم طريقة لأخذ القرار بإعادة الانتشار الأفضل لبعض مكونات النظام الموزع عن طريق المراقبة الذاتية لحالة عقد النظام الموزع بالاستفادة من نظرية الأرتال، من ثم تقديم تقارير عن تلك الحالة إلى المكون المركزي، الذي يقوم حينئذٍ بأخذ قرار إعادة الانتشار إلى العقد المناسبة. Distributed Systems have been use too often recently as an alternative for central systems, due to their better performance when the size of the system or the need to the system resources becomes bigger. On the other hand, distributed systems are still fussing about the availability lack when a change of the infrastructure of the network take a place, which presents the approach of component redeployment in the distributed systems. In this research, we view a method for making decision about best component redeployment in a distributed system via self-monitoring for node status using the Queuing Theory, then handle reports to the central component, which make the choice about redeployment to the suitable node

Self-organization and autonomy in computational networks: agents-based contractual workflow paradigm

We describe an agents-based contractual workflow paradigm for Self-organization and autonomy in computational networks. The agent-based paradigm can be interpreted as the outcome arising out of deterministic, nondeterministic or stochastic interaction among a set of agents that includes the environment. These interactions are like chemical reactions and result in self-organization. Since the reaction rules are inherently parallel, any number of actions can be performed cooperatively or competitively among the subsets of elements, so that the agents carry out the required actions. Also we describe the application of this paradigm in finding short duration paths, chemical- patent mining, and in cloud computing services