Prototyping Component-Based Self-Adaptive Systems with Maude

Software adaptation is becoming increasingly important as more and more applications need to dynamically adapt their structure and behavior to cope with changing contexts, available resources and user requirements. Maude is a high-performance reflective language and system, supporting both equational and rewriting logic specification and programming for a wide range of applications. In this paper we describe our experience in using Maude for prototyping component-based self-adaptive systems so that they can be formally simulated and analyzed. In order to illustrate the benefits of using Maude in this context, a case study in the robotics domain is presented.Ministerio de Ciencia e Innovación TIN2009-08572Fundación Séneca-CARM 15374/PI/1

Towards an engine for coordination-based architectural reconfigurations

Software reconfigurability became increasingly relevant to the architectural process due to the crescent dependency of modern societies on reliable and adaptable systems. Such systems are supposed to adapt themselves to surrounding environmental changes with minimal service disruption, if any. This paper introduces an engine that statically applies reconfigurations to (formal) models of software architectures. Reconfigurations are specified using a domain specific language— ReCooPLa—which targets the manipulation of software coordinationstructures,typicallyusedinservice-orientedarchitectures(soa).Theengine is responsible for the compilation of ReCooPLa instances and their application to the relevant coordination structures. The resulting configurations are amenable to formal analysis of qualitative and quantitative (probabilistic) properties.This work is partly funded by ERDF - European Regional Development Fund through the COMPETE Programme (operational programme for competitiveness) and by National Funds through the FCT, the Portuguese Foundation for Science and Technology, within project FCOMP-01-0124-FEDER-028923. The second author is supported by an Individual Doctoral Grant from FCT, with reference SFRH/BD/71475/2010

Modeling the Artificial Immune System to the Human Immune System with the Use of Agents

The purpose of this study is to provide a model and a work frame to approximate the artificial immune system to the human immune system with the use of agents to counter malicious software (malware). The artificial immune system components are commercial off-the-shelf products that are managed by the agent that coordinate and synchronize their activity. The behavior of the agent is a simulation of the B-cells in the Human Immune System in the encapsulation, analysis and digestion of the antigen. The proposed architecture can be implemented in almost certainty based on the use of the commercial off-the-shelf products (COTS). The agent can be constructed to perform the required functionality with the help of the sandbox tools that provide the encapsulation. Anomaly detectors provide the knowledge of any process' action that is considered abnormal, hence, a possible malware. The Antivirus applications provide the digestion of the antigen, where known malware is handled directly, while unknown malware is analyzed by signature extraction, then handled by the antivirus. Other components such as intrusion detection (ID) applications perform the defenses at the entrances to the system (communication channels) and the firewall applications provide the prevention of the spread of the antigen and quarantining it in the infected node. The implementation of the model will provide a parallel self-healing system against antigens along side the applications and hardware self-healing systems.Computer Science Departmen

Feature interaction in composed systems. Proceedings. ECOOP 2001 Workshop #08 in association with the 15th European Conference on Object-Oriented Programming, Budapest, Hungary, June 18-22, 2001

Feature interaction is nothing new and not limited to computer science. The problem of undesirable feature interaction (feature interaction problem) has already been investigated in the telecommunication domain. Our goal is the investigation of feature interaction in componet-based systems beyond telecommunication. This Technical Report embraces all position papers accepted at the ECOOP 2001 workshop no. 08 on "Feature Interaction in Composed Systems". The workshop was held on June 18, 2001 at Budapest, Hungary

Graph Based Verification of Software Evolution Requirements

Due to market demands and changes in the environment, software systems have to evolve. However, the size and complexity of the current software systems make it time consuming to incorporate changes. During our collaboration with the industry, we observed that the developers spend much time on the following evolution problems: designing runtime reconfigurable software, obeying software design constraints while coping with evolution, reusing old software solutions for new evolution problems. This thesis presents 3 processes and tool suits that aid the developers/designers when tackling these problems.\ud The first process and tool set allow early verification of runtime reconfiguration requirements. In this process the UML models are converted into a graph-based model. The execution semantics of UML are modeled by graph transformation rules. Using these graph transformation rules, the execution of the UML models is simulated. The simulation generates a state-space showing all possible reconfigurations. The runtime reconfiguration requirements are expressed by computational tree logic or with a visual state-based language, which are verified over the generated state-space. When the verification fails a feedback on the problem is provided.\ud The second process and tool set are developed for computer aided detection of static program constraint violations. We developed a modeling language called Source Code Modeling Language (SCML) in which program elements from the source code can be represented. In the proposed process for constraint violation detection, the source code is converted into SCML models. The constraint detection is realized by graph transformation rules. The rules detect the violation and extract information from the SCML model to provide feedback on the location of the problem.\ud The third process and tool set provide computer aided verification of whether a design idiom can be used to implement a change request. The developers tend to implement evolution requests using software structures that are familiar to them; called design idioms. Graph transformations are used for detecting whether the constraints of the design idiom are satisfied or not. For a given design idiom and given source files in SCML, the implementation of the idiom is simulated. If the simulation succeeds, then the models are converted to source code.\u

Algebraic software architecture reconfiguration

The ability of reconfiguring software architectures in order to adapt them to new requirements or a changing environment has been of growing interest, but there is still not much formal work in the area. Most existing approaches deal with run-time changes in a deficient way. The language to express computations is often at a very low level of specification, and the integration of two different formalisms for the computations and reconfigurations require sometimes substantial changes. To address these problems, we propose a uniform algebraic approach with the following characteristics. 1. Components are written in a high-level program design language with the usual notion of state. 2. The approach combines two existing frameworks -- one to specify architectures, the other to rewrite labelled graphs -- just through small additions to either of them. 3. It deals with certain typical problems such as guaranteeing that new components are introduced in the correct state (possib..