A Framework for Agile Development of Component-Based Applications

Agile development processes and component-based software architectures are two software engineering approaches that contribute to enable the rapid building and evolution of applications. Nevertheless, few approaches have proposed a framework to combine agile and component-based development, allowing an application to be tested throughout the entire development cycle. To address this problematic, we have built CALICO, a model-based framework that allows applications to be safely developed in an iterative and incremental manner. The CALICO approach relies on the synchronization of a model view, which specifies the application properties, and a runtime view, which contains the application in its execution context. Tests on the application specifications that require values only known at runtime, are automatically integrated by CALICO into the running application, and the captured needed values are reified at execution time to resume the tests and inform the architect of potential problems. Any modification at the model level that does not introduce new errors is automatically propagated to the running system, allowing the safe evolution of the application. In this paper, we illustrate the CALICO development process with a concrete example and provide information on the current implementation of our framework

Dynamic Model-based Management of Service-Oriented Infrastructure.

Models are an effective tool for systems and software design. They allow software architects to abstract from the non-relevant details. Those qualities are also useful for the technical management of networks, systems and software, such as those that compose service oriented architectures. Models can provide a set of well-defined abstractions over the distributed heterogeneous service infrastructure that enable its automated management. We propose to use the managed system as a source of dynamically generated runtime models, and decompose management processes into a composition of model transformations. We have created an autonomic service deployment and configuration architecture that obtains, analyzes, and transforms system models to apply the required actions, while being oblivious to the low-level details. An instrumentation layer automatically builds these models and interprets the planned management actions to the system. We illustrate these concepts with a distributed service update operation

Improving perceptual multimedia quality with an adaptable communication protocol

Copyrights @ 2005 University Computing Centre ZagrebInnovations and developments in networking technology have been driven by technical considerations with little analysis of the benefit to the user. In this paper we argue that network parameters that define the network Quality of Service (QoS) must be driven by user-centric parameters such as user expectations and requirements for multimedia transmitted over a network. To this end a mechanism for mapping user-oriented parameters to network QoS parameters is outlined. The paper surveys existing methods for mapping user requirements to the network. An adaptable communication system is implemented to validate the mapping. The architecture adapts to varying network conditions caused by congestion so as to maintain user expectations and requirements. The paper also surveys research in the area of adaptable communications architectures and protocols. Our results show that such a user-biased approach to networking does bring tangible benefits to the user

An approach to relate business and application services using ISDL

This paper presents a service-oriented design approach that allows one to relate services modelled at different levels of granularity during a design process, such as business and application services. To relate these service models we claim that a 'concept gap' and an 'abstraction gap' need to be bridged. The concept gap represents the difference between the conceptual models used to construct service models by different stakeholders involved in the design process. The abstraction gap represents the difference in abstraction level at which service models are defined. Two techniques are presented that bridge these gaps. Both techniques are based on the Interaction System Design Language (ISDL). The paper illustrates the use of both techniques through an example

ICIS 2007 Panel Report: Bridging Service Computing and Service Management: How MIS Contributes to Service Orientation

Service computing has become the new frontier of enterprise computing in the continued pursuit of organizational agility. Many major corporations are in the midst of implementing significant initiatives to re-architect their IT through service computing to help meet fast changing business requirements. As a result, many new and interesting research questions arise in this area, spanning technical, organizational, and economic issues. Currently, there is a great need for a framework for aligning the issues of technology and management in the era of service computing. This paper outlines the key points presented at the International Conference on Information Systems 2007 panel on Bridging Service Computing and Service Management. The first few sections of the paper contain viewpoints of each panelist on why and how MIS should take leadership in this research area. Then, a joint perspective on bridging service computing and service management is presented

Orchestration of heterogeneous middleware services and its application to a comand and control platform

MSC Dissertation in Computer EngineeringDistributed objects was, until recently, the leading technology in the design and implementation of component-based architectures, such as the ones based on services, better known as Service-Oriented Architectures (SOA). Although established in the market for more than a decade, and therefore mature, these technologies have failed to overcome the porting of the SOA concept to the Web. Web services are a recent technology that has been growing in the last few years. Their acceptance has increased over enterprises and organizations as they seem to overcome the Web and interoperability related problems of the Distributed Objects technology. Web services provide interoperability between systems and that is undoubtedly a strength of this technology since this is a crucial aspect of nowadays business. Moreover, the widespread of services led to the recent introduction of the service composition concept, that although being a technology independent concept,is closely related to Web services and there is no tool support for other technologies. Nonetheless, distributed objects still play an important role in the development of distributed systems, namely due to performance issues that are important when it comes to the internals of a platform. However, the use of service composition in these distributed object-based platforms requires the exposure of their composing services as Web services. The main objective of this masters thesis is improve the state-of-the-art in the support for the composition of services originating from distributed objects-based platforms. Bearing in mind that these kind of platforms are composed by several services, the idea is to present a platform as a set of Web services in order to be able to orchestrate them