Enfoques emergentes de ingeniería de software aplicados a grid computing

Las aplicaciones para Grid computing basadas en servicios Grid, pueden beneficiarse con el empleo de algunos de los emergentes enfoques de ingeniería de software. Los servicios Web, de los cuales extienden los servicios Grid, son intensamente investigados con el objetivo de desarrollar soluciones basadas en SOA que permitan reutilizarlos, evolucionar y soportar cambios de manera automatizada. Analizamos de qué manera los nuevos enfoques de ingeniería de software se aplicaron en el campo de Grid computing y proponemos el empleo de uno de ellos en la composición de servicios Grid.Eje: ingeniería de softwareRed de Universidades con Carreras en Informática (RedUNCI

Initialisation Problems in Feature Composition

Composing features that have inconsistent requirements may lead to feature interactions that violate requirements satisfied by each feature in isolation. These interactions manifest themselves as conflicts on shared resources. Arbitration is a common approach to resolving such conflicts that uses prioritisation to decide which feature has access to resources when there is a conflict. However, arbitration alone does not guarantee satisfaction of the requirement of the feature that eventually gains access to a resource. This is because arbitration does not take into account that the resource may be in a state that is inconsistent with that expected by the feature. We call this the initialisation problem. In this thesis we propose an approach to addressing the initialisation problem which combines arbitration with contingencies. Contingency means having several specifications per feature satisfying the same requirement, depending on the current resource state. We illustrate and validate our approach by applying it to resolving conflicts between features in smart home and automotive domains. The validation shows that contingencies complement arbitration by enabling satisfaction of the requirement of the feature that eventually gains access to a shared resource, regardless of the current state of the resource. The main contribution of this thesis is an approach to analysing initialisation concerns in feature composition. At the core of our approach is an explicit consideration of all possible states of a resource as potential initial states. Given each initial state we then derive corresponding specifications that would enable a feature to satisfy its requirement in those states. We show that our approach to initialisation problems is relevant to addressing the feature interaction problem by characterising some types of conflicts as initialisation concerns

A formal verification approach of conversations in compostie Web services

Web service composition is nowadays a very focused-on topic of research by academic and industrial research groups. This thesis discusses the design and verification of behaviors of composite web services. To model composite web services, two behaviors are proposed, namely control and operational. The operational behavior shows the business logic of the process functionality for a composite web service. The control behavior shows the constraints that the operational behavior should satisfy and specifies the states that this behavior should be in. The idea behind this separation is to promote the design, verification and reusability of web services in composite settings. To guarantee their compatibility, these two behaviors communicate and synchronize through conversation messages. State charts are used to model composite web services and symbolic model checking with NuSMV model checker is used to verify their conversations. The properties to be verified are expressed in two logics: Linear Temporal Logic (LTL) and Computation Tree Logic (CTL). A Java-based translation procedure from the design model to SMV program used by NuSMV has been developed and tested in two case studie

Features Interaction Detection and Resolution in Smart home systems Using Agent-Based Negotiation Approach

Smart home systems (SHS) have become an increasingly important technology in modern life. Apart from safety, security, convenience and entertainment, they offer significant potential benefits for the elderly, disabled and others who cannot live independently. Furthermore, smart homes are environmentally friendly. SHS functionality is based on perceiving residents’ needs and desires, then offering services accordingly. In order to be smart, homes have to be equipped with sensors, actuators and intelligent devices and appliances, as well as connectivity and control mechanisms. A typical SHS comprises heterogeneous services and appliances that are designed by many different developers and which may meet for the first time in the home network. The heterogeneous nature of the systems, in addition to the dynamic environment in which they are deployed, exposes them to undesirable interactions between services, known as Feature Interaction (FI). Another reason for FI is the divergence between the policies, needs and desires of different residents. Proposed approaches to FI detection and resolution should take these different types of interaction into account. Negotiation is an effective mechanism to address FI, as conflicting features can then negotiate with each other to reach a compromise agreement. The ultimate goal of this study is to develop an Agent-Based Negotiation Approach (ABNA) to detect and resolve feature interaction in a SHS. A smart home architecture incorporating the components of the ABNA has been proposed. The backbone of the proposed approach is a hierarchy in which features are organised according to their importance in terms of their functional contribution to the overall service. Thus, features are categorised according to their priority, those which are essential for the service to function having the highest priority. An agent model of the ABNA is proposed and comprehensive definitions of its components are presented. A computational model of the system also has been proposed which is used to explain the behaviour of different components when a proposal to perform a task is raised. To clarify the system requirements and also to aid the design and implementation of its properties, a formal specification of the ABNA is presented using the mathematical notations of Calculus of Context-aware Ambient (CCA), then in order to evaluate the approach a case study is reported, involving two services within the SHS: ventilation and air conditioning. For the purpose of evaluation, the execution environment of CCA is utilised to execute and analyse the ABNA

Web service composition : architecture, frameworks, and techniques

OASIS defines Service Oriented Architecture (SOA) as a paradigm for organizing and utilizing distributed capabilities that may be under the control of different ownership domains. One approach to realize SOA is Web services. A Web service is a software system that has a machine processable Web Services Description Language (WSDL) interface; other systems interact with it using SOAP messages in a manner prescribed by its description. Descriptions enable Web services to be discovered, used by other Web services, and composed into new Web services. Composition is a mechanism for rapid creation of new Web services by reusing existing ones. Web services have functional, behavioral, semantic, and non-functional characteristics. These characteristics have to be considered for composition, as they provide essential information about the services. In order to compose Web services with these characteristics, they have to be described appropriately. However, the existing techniques do not consider all these aspects together for description and composition. This thesis proposes a business model, also referred to as architecture, a description framework, and a composition framework for Web service composition. Techniques for matching, categorizing, and assembling the composite services are also proposed as a part of the composition framework. The architecture, frameworks, and techniques describe, discover, manipulate, and compose Web services by taking into account all their characteristics. The standard Web service business model is extended by the proposed business model to support Web service composition. In the model, based on their demand, the requested Web services are composed by the Web service composer. In the proposed architecture, Web services are described using the description framework languages. The proposed framework combines Semantic Annotations for WSDL and XML Schema (SAWSDL) for functional and semantic description, Message Sequence Charts (MSC) for behavioral description, and a simple and new Non Functional Specification Language (NFSL) for the non-functional properties description of Web services. It uses Higher Order Logic (HOL) for formalizing and integrating the three languages. The role of Web service composer in the architecture is realized by the composition framework. It essentially defines the architecture of the composer. In this framework, matchmaking, categorization, and assembly techniques are used to create the requested composite service. These techniques manipulate the Web services at HOL-level. The formal matchmaking technique discovers the primitive Web services by using a HOL theorem prover. The categorization and the assembly techniques manipulate the matched services and orchestrate the composite service. The concepts of the model, frameworks, and techniques are implemented, and their working is illustrated using case studies. Prototypes of the model's components (extended registry and extended requester) and the composition framework are developed, and their performance is analyzed. Case studies to illustrate the description and the composition frameworks are also presente

Detection of Feature Interactions in Automotive Active Safety Features

With the introduction of software into cars, many functions are now realized with reduced cost, weight and energy. The development of these software systems is done in a distributed manner independently by suppliers, following the traditional approach of the automotive industry, while the car maker takes care of the integration. However, the integration can lead to unexpected and unintended interactions among software systems, a phenomena regarded as feature interaction. This dissertation addresses the problem of the automatic detection of feature interactions for automotive active safety features. Active safety features control the vehicle's motion control systems independently from the driver's request, with the intention of increasing passengers' safety (e.g., by applying hard braking in the case of an identified imminent collision), but their unintended interactions could instead endanger the passengers (e.g., simultaneous throttle increase and sharp narrow steering, causing the vehicle to roll over). My method decomposes the problem into three parts: (I) creation of a definition of feature interactions based on the set of actuators and domain expert knowledge; (II) translation of automotive active safety features designed using a subset of Matlab's Stateflow into the input language of the model checker SMV; (III) analysis using model checking at design time to detect a representation of all feature interactions based on partitioning the counterexamples into equivalence classes. The key novel characteristic of my work is exploiting domain-specific information about the feature interaction problem and the structure of the model to produce a method that finds a representation of all different feature interactions for automotive active safety features at design time. My method is validated by a case study with the set of non-proprietary automotive feature design models I created. The method generates a set of counterexamples that represent the whole set of feature interactions in the case study.By showing only a set of representative feature interaction cases, the information is concise and useful for feature designers. Moreover, by generating these results from feature models designed in Matlab's Stateflow translated into SMV models, the feature designers can trace the counterexamples generated by SMV and understand the results in terms of the Stateflow model. I believe that my results and techniques will have relevance to the solution of the feature interaction problem in other cyber-physical systems, and have a direct impact in assessing the safety of automotive systems

On feature interactions among web services

Web services promise to allow businesses to adapt rapidly to changes in the business environment, and the needs of different customers. However, the rapid introduction of new services paired with the dynamicity of the business environment also leads to undesirable interactions that negatively impact service quality and user satisfaction. In this paper, we propose an approach for modeling such undesirable interactions as feature interactions. Our approach for detecting interactions is based on goal-oriented analysis and scenario modeling. It allows us to reason about feature interactions in terms of goal conflicts, and feature deployment. Two case studies illustrate the approach. The paper concludes with a discussion, and an outlook on future research

On Feature Interactions among Web Services

Web services promise to allow businesses to adapt rapidly to changes in the business environment, and the needs of different customers. However, the rapid introduction of new services paired with the dynamicity of the business environment also leads to undesirable interactions that negatively impact service quality and user satisfaction. In this paper, we propose an approach for modeling such undesirable interactions as feature interactions. As each functional feature is ultimately motivated by non-functional requirements, we make an explicit distinction between functional and non-functional features. We then describe our approach for detecting and resolving feature interactions among web services. The approach is based on goal-oriented analysis and scenario modeling. It allows us to reason about feature interactions in terms of goal conflicts and feature deployment. Three case studies illustrate the approach. The paper concludes with a discussion of our findings and an outlook on future research. KEYWORDS: Feature Interaction, Web Services, Goal-oriented Analysis, Non-Functional Feature