Technical factors for implementing SOA-Based business intelligence architecture : an exploratory study

Business intelligence (BI) architecture based on service-oriented architecture (SOA) concept enables enterprises to deploy agile and reliable BI applications. However, the key factors for implementing a SOA-based BI architecture from technical perspectives have not yet been systematically investigated. Most of the prior studies focus on organisational and managerial perspectives rather than technical factors. Therefore, this study explores the key technical factors that are most likely to have an impact on the implementation of a SOA-based BI architecture. This paper presents a conceptual model of BI architecture built on SOA concept. Drawing on academic and practitioner literature related to SOA and software architectural design, we propose fourteen key factors that may influence the implementation of a SOA-based BI architecture. This study bridges the gap between academic and practitioners.

Broker-based service-oriented content adaptation framework

Content adaptation bridges the mismatch between rich contents and user preferences along with the end device capability. This thesis addresses five key issues: enabling content adaptation as services; locating and selecting best possible services in the network; and negotiating, providing and managing quality assurance of a service.

Management of service level agreement for service-oriented content adaptation platform

It is paramount to provide seamless and ubiquitous access to rich contents available online to interested users via a wide range of devices with varied characteristics. Recently, a service-oriented content adaptation scheme has emerged to address this content-device mismatch problem. In this scheme, content adaptation functions are provided as services by third-party providers. Clients pay for the consumed services and thus demand service quality. As such, negotiating for the QoS offers, assuring negotiated QoS levels and accuracy of adapted content version are essential. Any non-compliance should be handled and reported in real time. These issues elevate the management of service level agreement (SLA) as an important problem. This chapter presents prior work, important challenges, and a framework for managing SLA for service-oriented content adaptation platform.

A multilevel trust management framework for service oriented environment

In service-oriented computing applications, trust management systems are emerging as a promising technology to improve the e-commerce consumers and provider's relationship. Both consumers and providers need to evaluate the trust levels of potential partners before engaging in interactions. The accuracy of trust evaluation greatly affects the success rate of the interaction. This paper addresses the threats and challenges that can compromise the reliability of the current trust management system. This paper studies and examines the importance of the trust factors of the trust management framework, specifically in dealing with malicious feedback ratings from e-commerce users. To improve the reliability of the trust management systems, an approach that addresses feedback-related vulnerabilities is paramount. A multilevel trust management system computes trust by combining different types of information. Using this combination, we introduce a multilevel framework for a new interactive trust management to improve the correctness in estimate of trust information.

Recover fault services via complex service-to-node mappings in wireless sensor networks

With the motivation of seamlessly extending wireless sensor networks to the external environment, service-oriented architecture comes up as a promising solution. However, as sensor nodes are failure prone, this consequently renders the whole wireless sensor network to seriously faulty. When a particular node is faulty, the service on it should be migrated into those substitute sensor nodes that are in a normal status. Currently, two kinds of approaches exist to identify the substitute sensor nodes: the most common approach is to prepare redundancy nodes, though the involved tasks such as maintaining redundancy nodes, i.e., relocating the new node, lead to an extra burden on the wireless sensor networks. More recently, other approaches without using redundancy nodes are emerging, and they merely select the substitute nodes in a sensor node's perspective i.e., migrating the service of faulty node to it's nearest sensor node, though usually neglecting the requirements of the application level. Even a few work consider the need of the application level, they perform at packets granularity and don't fit well at service granularity. In this paper, we aim to remove these limitations in the wireless sensor network with the service-oriented architecture. Instead of deploying redundancy nodes, the proposed mechanism replaces the faulty sensor node with consideration of the similarity on the application level, as well as on the sensor level. On the application level, we apply the Bloom Filter for its high efficiency and low space costs. While on the sensor level, we design an objective solution via the coefficient of a variation as an evaluation for choosing the substitute on the sensor level. © 2014 Springer Science+Business Media New York.

Energy efficient sleep schedule with service coverage guarantee in wireless sensor networks

Service oriented architecture has been proposed to support collaborations among distributed wireless sensor network (WSN) applications in an open dynamic environment. However, WSNs are resource constraint, and have limited computation abilities, limited communication bandwidth and especially limited energy. Fortunately, sensor nodes in WSNs are usually deployed redundantly, which brings the opportunity to adopt a sleep schedule for balanced energy consumption to extend the network lifetime. Due to miniaturization and energy efficiency, one sensor node can integrate several sense units and support a variety of services. Traditional sleep schedule considers only the constraints from the sensor nodes, can be categorized to a one-layer (i.e., node layer) issue. The service oriented WSNs should resolve the energy optimization issue considering the two-layer constraints, i.e., the sensor nodes layer and service layer. Then, the one-layer energy optimization scheme in previous work is not applicable for service oriented WSNs. Hence, in this paper we propose a sleep schedule with a service coverage guarantee in WSNs. Firstly, by considering the redundancy degree on both the service level and the node level, we can get an accurate redundancy degree of one sensor node. Then, we can adopt fuzzy logic to integrate the redundancy degree, reliability and energy to get a sleep factor. Based on the sleep factor, we furthermore propose the sleep mechanism. The case study and simulation evaluations illustrate the capability of our proposed approach.

Um estudo empírico sobre os benefícios de SOA nas empresas: a visão dos profissionais de TI

Este trabalho tem como objetivo principal a avaliação da percepção dos profissionais de tecnologia de informação quanto aos benefícios atribuídos a arquitetura orientada a serviço (SOA). Em busca deste objetivo, e visando uma melhor compreensão do tema, estudos teóricos foram desenvolvidos abordando os seguintes assuntos: Arquitetura de Software, Gerenciamento de Processos de Negócio (BPM) e Arquiteturas Orientadas a Serviços (SOA). A partir do referencial teórico e de um grupo de foco – composto por seis profissionais experientes em SOA – oito hipóteses foram levantadas, representando os principais benefícios atribuídos a estas arquiteturas. Um questionário foi então preparado e, a partir dele, 66 respostas válidas foram obtidas. Os resultados foram analisados utilizando-se de estatísticas descritivas e dos testes estatísticos não-paramétricos de Wilcoxon e qui-quadrado, buscando a validação, ou rejeição, das hipóteses apresentadas. Como resultado, em suma, percebe-se que, apesar da recente adoção das SOAs pelas empresas brasileiras, parece haver uma consonância entre seus profissionais de TI quanto aos benefícios desta nova abordagem para projetos de tecnologia da informação. Evidencia-se também a grande importância de disciplinas como governança e planejamento para a garantia do sucesso na implantação de projetos baseados nestas arquiteturas.

A framework for monitoring and runtime recovery of web service-based applications

Service provisioning is a challenging research area for the design and implementation of autonomic service-oriented software systems. It includes automated QoS management for such systems and their applications. Monitoring, Diagnosis and Repair are three key features of QoS management. This work presents a self-healing Web service-based framework that manages QoS degradation at runtime. Our approach is based on proxies. Proxies act on meta-level communications and extend the HTTP envelope of the exchanged messages with QoS-related parameter values. QoS Data are filtered over time and analysed using statistical functions and the Hidden Markov Model. Detected QoS degradations are handled with proxies. We experienced our framework using an orchestrated electronic shop application (FoodShop).

A Methodology for Building Service-Oriented Applications in the Presence of Non-Functional Properties

This thesis presents ⇡SOD-M (Policy-based Service Oriented Development Methodology), a methodology for modeling reliable service-based applications using policies. It proposes a model driven method with: (i) a set of meta-models for representing non-functional constraints associated to service-based applications, starting from an use case model until a service composition model; (ii) a platform providing guidelines for expressing the composition and the policies; (iii) model-to-model and model-to-text transformation rules for semi-automatizing the implementation of reliable service-based applications; and (iv) an environment that implements these meta-models and rules, and enables the application of ⇡SOD-M. This thesis also presents a classification and nomenclature for non-functional requirements for developing service-oriented applications. Our approach is intended to add value to the development of service-oriented applications that have quality requirements needs. This work uses concepts from the service-oriented development, non-functional requirements design and model-driven delevopment areas to propose a solution that minimizes the problem of reliable service modeling. Some examples are developed as proof of concepts

Formalizing languages for service oriented computing

Service Oriented Computing is a new programming paradigm for addressing distributed system design issues. Services are autonomous computational entities which can be dynamically discovered and composed in order to form more complex systems able to achieve different kinds of task. E-government, e-business and e-science are some examples of the IT areas where Service Oriented Computing will be exploited in the next years. At present, the most credited Service Oriented Computing technology is that of Web Services, whose specifications are enriched day by day by industrial consortia without following a precise and rigorous approach. This PhD thesis aims, on the one hand, at modelling Service Oriented Computing in a formal way in order to precisely define the main concepts it is based upon and, on the other hand, at defining a new approach, called bipolar approach, for addressing system design issues by synergically exploiting choreography and orchestration languages related by means of a mathematical relation called conformance. Choreography allows us to describe systems of services from a global view point whereas orchestration supplies a means for addressing such an issue from a local perspective. In this work we present SOCK, a process algebra based language inspired by the Web Service orchestration language WS-BPEL which catches the essentials of Service Oriented Computing. From the definition of SOCK we will able to define a general model for dealing with Service Oriented Computing where services and systems of services are related to the design of finite state automata and process algebra concurrent systems, respectively. Furthermore, we introduce a formal language for dealing with choreography. Such a language is equipped with a formal semantics and it forms, together with a subset of the SOCK calculus, the bipolar framework. Finally, we present JOLIE which is a Java implentation of a subset of the SOCK calculus and it is part of the bipolar framework we intend to promote.

Workflow Patterns for Service Oriented Computing in JOLIE

Il presente lavoro di tesi ha come punto focale la descrizione, la verifica e la dimostrazione della realizzabilità dei Workflow Patterns di Gestione del Flusso(Control-Flow) e Risorse (Resource) definiti da parte della Workflow Pattern Initiative (WPI)in JOLIE, un innovativo linguaggio di programmazione orientato ai servizi nato nell'ambito del Service Oriented Computing. Il Service Oriented Computing (SOC) è un nuovo modo di pensare la programmazione di applicazioni distribuite, i cui concetti fondamentali sono i servizi e la composizione. L’approccio SOC definisce la possibilità di costruire un’applicazione in funzione dei servizi che ne realizzano il comportamento tramite una loro composizione, definita secondo un particolare flusso di lavoro. Allo scopo di fornire la necessaria conoscenza per capire la teoria, le meccaniche e i costrutti di JOLIE utilizzati per la realizzazione dei pattern, il seguente lavoro di tesi è stato diviso in quattro parti, corrispondenti ad altrettanti capitoli. Nel primo capitolo viene riportata una descrizione generale del SOC e della Business Process Automation (BPA), che costituisce l’ambiente in cui il SOC è inserito. Per questo viene fatta una disamina della storia informatica sui sistemi distribuiti, fino ad arrivare ai sistemi odierni, presentando in seguito il contesto del BPA e delle innovazioni derivanti dalle sue macro-componenti, di cui il SOC fa parte. Continuando la descrizione dell’approccio Service Oriented, ne vengono presentati i requisiti (pre-condizioni) e si cerca di dare una definizione precisa del termine “servizio”, fino all'enunciazione dei principi SOC declinati nell’ottica delle Service Oriented Architectures, presentando in ultimo i metodi di composizione dei servizi, tramite orchestrazione e coreografia. L’ultima sezione del capitolo prende in considerazione il SOC in un’ottica prettamente industriale e ne evidenzia i punti strategici. Il secondo capitolo è incentrato sulla descrizione di JOLIE, gli aspetti fondamentali dell’approccio orientato ai servizi, che ne caratterizzano profondamente la definizione concettuale (SOCK), e la teoria della composizione dei servizi. Il capitolo non si pone come una descrizione esaustiva di tutte le funzionalità del linguaggio, ma considera soprattutto i concetti teorici, le strutture di dati, gli operatori e i costrutti di JOLIE utilizzati per la dimostrazione della realizzabilità dei Workflow Pattern del capitolo successivo. Il terzo capitolo, più lungo e centrale rispetto agli altri, riguarda la realizzazione dei workflow pattern in JOLIE. All'inizio del capitolo viene fornita una descrizione delle caratteristiche del WPI e dei Workflow Pattern in generale. In seguito, nelle due macro-sezioni relative ai Control-Flow e Resource pattern vengono esposte alcune nozioni riguardanti le metodologie di definizione dei pattern (e.g. la teoria sulla definizione delle Colored Petri Nets) e le convezioni adottate dal WPI, per passare in seguito al vero e proprio lavoro (sperimentale) di tesi riguardo la descrizione dei pattern, l’analisi sulla loro realizzabilità in JOLIE, insieme ad un codice di esempio che esemplifica quanto affermato dall'analisi. Come sommario delle conclusioni raggiunte sui pattern, alla fine di ognuna delle due sezioni definite in precedenza, è presente una scheda di valutazione che, con lo stesso metodo utilizzato e definito dalla WPI, permette di avere una rappresentazione generale della realizzabilità dei pattern in JOLIE. Il quarto capitolo riguarda gli esiti tratti dal lavoro di tesi, riportando un confronto tra le realizzazioni dei pattern in JOLIE e le valutazioni del WPI rispetto agli altri linguaggi da loro considerati e valutati. Sulla base di quanto ottenuto nel terzo capitolo vengono definite le conclusioni del lavoro portato avanti sui pattern e viene delineato un’eventuale scenario riguardante il proseguimento dell’opera concernente la validazione ed il completamento della studio. In ultimo vengono tratte alcune conclusioni sia riguardo JOLIE, nel contesto evolutivo del linguaggio e soprattutto del progetto open-source che è alla sua base, sia sul SOC, considerato nell’ambito del BPA e del suo attuale ambito di sviluppo dinamico.

Jolie - un linguaggio Service Oriented

Nella tesi vengono descritte le caratteristiche principali del linguaggio di programmazione service-oriented Jolie, analizzandone ampiamente la sintassi e proponendo esempi di utilizzo degli operatori e dei costrutti. Viene fatta una panoramica di SOC, SOA, Web Services, Cloud Computing, Orchestrazione, Coreografia, Deployment e Behaviour, gli ultimi due analizzati in diversi capitoli. La tesi si conclude con un esempio di conversione di servizi WSDL in Jolie, producendo un esempio di utilizzo del Web Service convertito. Nel documento vengono accennati i progressi storici del linguaggio ed i loro sviluppatori, nonché le API fornite dal linguaggio.