Automating the Composition of Middleware Configurations

A method is presented for the automatic construction of all possible valid compositions of different middleware software architectures. This allows reusing the latter in order to create systems providing a set of different non-functional properties. These compositions are constructed by using only the structural information of the architectures, i.e. their configurations. Yet, they provide a valuable insight on the different properties of the class of systems that can be constructed when a particular set of non-functional properties is required

Leveraging Semantic Web Service Descriptions for Validation by Automated Functional Testing

Recent years have seen the utilisation of Semantic Web Service descriptions for automating a wide range of service-related activities, with a primary focus on service discovery, composition, execution and mediation. An important area which so far has received less attention is service validation, whereby advertised services are proven to conform to required behavioural specifications. This paper proposes a method for validation of service-oriented systems through automated functional testing. The method leverages ontology-based and rule-based descriptions of service inputs, outputs, preconditions and effects (IOPE) for constructing a stateful EFSM specification. The specification is subsequently utilised for functional testing and validation using the proven Stream X-machine (SXM) testing methodology. Complete functional test sets are generated automatically at an abstract level and are then applied to concrete Web services, using test drivers created from the Web service descriptions. The testing method comes with completeness guarantees and provides a strong method for validating the behaviour of Web services

Investigating Decision Support Techniques for Automating Cloud Service Selection

The compass of Cloud infrastructure services advances steadily leaving users in the agony of choice. To be able to select the best mix of service offering from an abundance of possibilities, users must consider complex dependencies and heterogeneous sets of criteria. Therefore, we present a PhD thesis proposal on investigating an intelligent decision support system for selecting Cloud based infrastructure services (e.g. storage, network, CPU).Comment: Accepted by IEEE Cloudcom 2012 - PhD consortium trac

Verifying transactional requirements of web service compositions using temporal logic templates

Lecture notes in computer science, 2013, vol. 8180 LNCS (Part 1)Ensuring reliability in Web service compositions is of crucial interest as services are composed and executed in long-running, distributed mediums that cannot guarantee reliable communications. Towards this, transactional behavior has been proposed to handle and undo the effects of faults of individual components. Despite significant research interest, challenges remain in providing an easy-to-use, formal approach to verify transactional behavior of Web service compositions before costly development. In this paper, we propose the use of temporal logic templates to specify component-level and composition-level transactional requirements over a Web service composition. These templates are specified using a simple format, configured according to scope and cardinality, and automatically translated into temporal logic. To verify design conformance to a set of implemented templates, we employ model checking. We propose an algorithm to address state space explosion by reducing the models into semantically equivalent Kripke structures. Our approach facilitates the implementation of expressive transactional behavior onto existing complex services, as demonstrated in our experimental study.Scott Bourne, Claudia Szabo, and Quan Z. Shen

Towards a service-oriented e-infrastructure for multidisciplinary environmental research

Research e-infrastructures are considered to have generic and thematic parts. The generic part provids high-speed networks, grid (large-scale distributed computing) and database systems (digital repositories and data transfer systems) applicable to all research commnities irrespective of discipline. Thematic parts are specific deployments of e-infrastructures to support diverse virtual research communities. The needs of a virtual community of multidisciplinary envronmental researchers are yet to be investigated. We envisage and argue for an e-infrastructure that will enable environmental researchers to develop environmental models and software entirely out of existing components through loose coupling of diverse digital resources based on the service-oriented achitecture. We discuss four specific aspects for consideration for a future e-infrastructure: 1) provision of digital resources (data, models & tools) as web services, 2) dealing with stateless and non-transactional nature of web services using workflow management systems, 3) enabling web servce discovery, composition and orchestration through semantic registries, and 4) creating synergy with existing grid infrastructures

Coupling as a trade-off in an Enterprise Service Bus

Traditionally, integration problems between IT systems were solved by point-to-point connections. These point-to-point connections pose issues with scalability, reliability, and flexibility. To overcome these issues, companies typically invest in Enterprise Application Integration (EAI) using an Enterprise Service Bus (ESB) to integrate the IT systems through a central middleware infrastructure. EAI promises improvement of scalability, reliability, and flexibility by implementing loosely coupled integration solutions to realise loosely coupled IT systems. By wrongly implementing EAI on an ESB IT systems may still be tightly coupled and the issues with point-to-point connections could be recreated on the ESB. Currently there is no out-of-the-box solution to identify the integration solution where tight coupling causes these issues. The goal of this research is to investigate an approach to identify the coupling state in an Enterprise Service Bus and identify the integration solutions on an ESB which have a negative impact on the quality attributes due to tight coupling. The first step in the approach is applying a set of properties on the integration solutions to identify their coupling state. Manually identifying the coupling state is labour intensive, so it is automated by implementing a prototype with the Eclipse MoDisco framework. The second step in the approach is evaluating a trade-off between the risk of being in a certain coupling state and the efficiency loss of migrating to a less risky coupling state. With the outcome of the trade-off it can be ascertained whether or not it is beneficial to migrate to a different coupling state. The result of the approach is a list of integration solutions for which it would be beneficial to migrate to a different coupling state. This gives a concrete measure to be able to determine which integration solutions need to be improved to strive for the optimal balance between quality and the effort needed to realise quality. The approach was validated using the ESB implementation of a large European airport as a case study