Using real options to select stable Middleware-induced software architectures

The requirements that force decisions towards building distributed system architectures are usually of a non-functional nature. Scalability, openness, heterogeneity, and fault-tolerance are examples of such non-functional requirements. The current trend is to build distributed systems with middleware, which provide the application developer with primitives for managing the complexity of distribution, system resources, and for realising many of the non-functional requirements. As non-functional requirements evolve, the `coupling' between the middleware and architecture becomes the focal point for understanding the stability of the distributed software system architecture in the face of change. It is hypothesised that the choice of a stable distributed software architecture depends on the choice of the underlying middleware and its flexibility in responding to future changes in non-functional requirements. Drawing on a case study that adequately represents a medium-size component-based distributed architecture, it is reported how a likely future change in scalability could impact the architectural structure of two versions, each induced with a distinct middleware: one with CORBA and the other with J2EE. An option-based model is derived to value the flexibility of the induced-architectures and to guide the selection. The hypothesis is verified to be true for the given change. The paper concludes with some observations that could stimulate future research in the area of relating requirements to software architectures

Implementation of ontology for intelligent hospital ward

We have developed and implemented an ontology for an intelligent hospital ward. Our aim is to address the pervasiveness of computing applications in healthcare environments, which require: sharing of data across the hospital, including data generated by sensors and embedded in such environments, and dealing with semantic heterogeneity that exists across the hospital's data repositories. Our conceptual ontological model that supports such an environment has been implemented using semantic web tools and tested through the application developed with the J2EE technology

An enterprise modeling and integration framework based on knowledge discovery and data mining

This paper deals with the conceptual design and development of an enterprise modeling and integration framework using knowledge discovery and data mining. First, the paper briefly presents the background and current state-of-the-art of knowledge discovery in databases and data mining systems and projects. Next, enterprise knowledge engineering is dealt with. The paper suggests a novel approach of utilizing existing enterprise reference architectures, integration and modeling frameworks by the introduction of new enterprise views such as mining and knowledge views. An extension and a generic exploration of the information view that already exists within some enterprise models are also proposed. The Zachman Framework for Enterprise Architecture is also outlined versus the existing architectures and the proposed enterprise framework. The main contribution of this paper is the identification and definition of a common knowledge enterprise model which represents an original combination between the previous projects on enterprise architectures and the Object Management Group (OMG) models and standards. The identified common knowledge enterprise model has therefore been designed using the OMG's Model-Driven Architecture (MDA) and Common Warehouse MetaModel (CWM), and it also follows the RM-ODP (ISO/OSI). It has been partially implemented in Java(TM), Enterprise JavaBeans (EJB) and Corba/IDL. Finally, the advantages and limitations of the proposed enterprise model are outlined

Monitoring middleware for distributed applications

With growing maturity Internet services are proving integral to the provision of computer services. To provide consistent end-user experiences these services are increasingly augmented with some notion of 'Quality-of-Service' (QoS), which typically requires the management of computing resources to maintain a predictable level of service performance. It is difficult to guarantee consistent servIce provision In dynamic and open environments such as the Internet. However service monitoring can be used to inform compensatory actions by collecting meaningful service performance data from strategic points in an active service environment. Due to the unpredictable nature of the Internet distributed monitoring mechanisms face challenges with respect to the various communication protocols, application languages, and monitoring requirements associated with a service environment. With the growing popularity of Internet services creation of monitoring solutions on a per- service basis becomes time-consuming and misses opportunities to re-use existing logic. Ideally monitoring solutions would be domain-agnostic, automatically generated and automatically deployed. This thesis progresses these ambitions by providing a generic, distributed monitoring and evaluation framework based on Metric Collector (MeCo) components. These components can transparently gather measurement data across a range of service technologies as used within E-Commerce service environments. MeCo components form part of a framework which can interpret Service Level Agreements (SLAs) to automatically provide tailored service monitoring. The evaluation paradigms of the Meeo Framework are re-appropriated for use in Distributed Virtual Environments (DYEs). Quantifiable QoS requirements are established for Interest Management mechanisms (which limit message production based on object localities within a DYE). These are then incorporated into a DVE Simulator application. This application allows DYE application developers to evaluate Interest Management configurations for their suitability. Extensions to the DVE Simulator are exhibited in the Evolutionary Optimisation Simulator (EOS), which provides automated optimisation capabilities for DVE configurations through utilisation of genetic algorithm techniques.EThOS - Electronic Theses Online ServiceGBUnited Kingdo

COTS GIS Integration and its Soap-Based Web Services

In the modern geographic information systems, COTS software has been playing a major role. However, deploying heterogeneous GIS software has the tendency to form fragmented data sets and to cause inconsistency. To accomplish data consolidation, we must achieve interoperability between different GIS tools. In my thesis project, I developed Vector and Raster Data Adapters to implement the spatial data consolidation. I deployed ArcIMS to publish the spatial data and metadata onto Internet. Furthermore, the SOAP-Based GIS Web services are implemented to achieve the enterprise information system integration. The contribution of ours in this project is we have streamlined the COTS GIS server, the J2EE coordinator server, the web service provider components, and the COTS web publishing tools into a hybrid web service architecture, in which the enterprise information system integration, the web publishing, and the business-to business online services are uniformed

COTS GIS Integration and its Soap-Based Web Services

In the modern geographic information systems, COTS software has been playing a major role. However, deploying heterogeneous GIS software has the tendency to form fragmented data sets and to cause inconsistency. To accomplish data consolidation, we must achieve interoperability between different GIS tools. In my thesis project, I developed Vector and Raster Data Adapters to implement the spatial data consolidation. I deployed ArcIMS to publish the spatial data and metadata onto Internet. Furthermore, the SOAP-Based GIS Web services are implemented to achieve the enterprise information system integration. The contribution of ours in this project is we have streamlined the COTS GIS server, the J2EE coordinator server, the web service provider components, and the COTS web publishing tools into a hybrid web service architecture, in which the enterprise information system integration, the web publishing, and the business-to business online services are uniformed

Context caches in the clouds

In context-aware systems, the contextual information about human and computing situations has a strong temporal aspect i.e. it remains valid for a period of time. This temporal property can be exploited in caching mechanisms that aim to exploit such locality of reference. However, different types of contextual information have varying temporal validity durations and a varied spectrum of access frequencies as well. Such variation affects the suitability of a single caching strategy and an ideal caching mechanism should utilize dynamic strategies based on the type of context data, quality of service heuristics and access patterns and frequencies of context consuming applications. This paper presents an investigation into the utility of various context-caching strategies and proposes a novel bipartite caching mechanism in a Cloud-based context provisioning system. The results demonstrate the relative benefits of different caching strategies under varying context usage scenarios. The utility of the bipartite context caching mechanism is established both through simulation and deployment in a Cloud platform

Coping with evolution in information systems: a database perspective

Business organisations today are faced with the complex problem of dealing with evolution in their software information systems. This effectively concerns the accommodation and facilitation of change, in terms of both changing user requirements and changing technological requirements. An approach that uses the software development life-cycle as a vehicle to study the problem of evolution is adopted. This involves the stages of requirements analysis, system specification, design, implementation, and finally operation and maintenance. The problem of evolution is one requiring proactive as well as reactive solutions for any given application domain. Measuring evolvability in conceptual models and the specification of changing requirements are considered. However, even "best designs" are limited in dealing with unanticipated evolution, and require implementation phase paradigms that can facilitate an evolution correctly (semantic integrity), efficiently (minimal disruption of services) and consistently (all affected parts are consistent following the change). These are also discussedComputingM. Sc. (Information Systems

Evolution of web-based systems in model driven architecture

EThOS - Electronic Theses Online ServiceGBUnited Kingdo

Extending an open source enterprise service bus for multi-tenancy support focusing on administration and management

As part of cloud computing, the service model Platform-as-a-Service (PaaS) has emerged, where customers can develop and host internet-scale applications on cloud infrastructure. The Enterprise Service Bus (ESB) is one possible building block of a PaaS offering, providing integration capabilities for service-oriented architectures. Bringing the ESB to the cloud requires scalability and multi-tenancy support. When applied, these characteristics lead to economies of scale, reducing the costs per customer. In this diploma thesis we specify, design, and implement a multi-tenant management application for an existing open source ESB. The management application grants tenant users limited configuration access to the ESB’s connectivity and integration services. A tenant registry and a service registry serve as platform-wide databases. We ensure data isolation between tenants for the management application and ESB message flows. Furthermore, the management application can control clusters of ESB instances, retaining elasticity. These goals also involve extensions to the ESB itself, which implements the Java Business Integration (JBI) specification. As a result, an integration scenario emerged from the EU-funded project 4CaaSt was applied to the system