Automated transformation of BMF programs

Transformation is key to any program improvement process and a key to successful transformation is the medium in which it takes place. BMF (Bird-Meertens Formalism)is a medium specialised for program improvement via incremental ransformation. While much theoretical work exists, there has, to date, been a paucity of actual implementations employing BMF in an automated process of program improvement. In this paper we describe such an implementation, targeted to distributed architectures

Java coglets

Copyright © 2002 IEEEThis position paper considers how existing Grid infrastructure can be use to support Java computation on the Grid. We are interested in a class of Java applications characterize by distributed, mobile code. We identify and address these problems by building upon existing Grid services, resulting in a propose infrastructure called Coglets that supports homogenous, secure access to Java-enabled Grid resources.Darren Webb and Andrew L. Wendelbor

Developing an ontology for the domain name system

©2005 IEEE. Personal use of this material is permitted. However, permission to reprint/republish this material for advertising or promotional purposes or for creating new collective works for resale or redistribution to servers or lists, or to reuse any copyrighted component of this work in other works must be obtained from the IEEE.Ontologies provide a means of modelling and representing a knowledge domain. Such representation, already used in purpose-built distributed information systems, can also be of great value when applied to existing distributed information systems. The domain name system (DNS) provides a wide-area distributed name resolution system which is used extensively across the Internet. Changing the type and nature of resource records stored in the DNS currently requires an extensive request for comment procedure which takes a substantial amount of time, as the change has to be made globally. We propose an ontology for a DNS zone file, to provide a machine readable codification of the DNS and a mechanism for allowing local changes to the stored and represented structure of DNS records, using the extensible nature of OWL to allow local variations without having to go through the manual RFC procedure. This ontologically based system replaces a slow manual procedure with a rapid, machine-realisable procedure based on a uniform ontological representation of significant DNS knowledge. This paper discusses the application of ontologies to the DNS and how such an application can be built using OWL, the Web ontology language.Nickolas J. G. Falkner, Paul D. Coddington, Andrew L. Wendelbor

Distributed, parallel web service orchestration using XSLT

©2005 IEEE. Personal use of this material is permitted. However, permission to reprint/republish this material for advertising or promotional purposes or for creating new collective works for resale or redistribution to servers or lists, or to reuse any copyrighted component of this work in other works must be obtained from the IEEE.GridXSLT is an implementation of the XSLT programming language designed for distributed web service orchestration. Based on the functional semantics of the language, it compiles programs into dataflow graphs which can be efficiently executed across a collection of machines in a cluster or grid environment. Calls to web services can be made using the standard function call semantics provided by the language, and occur in parallel using the dataflow model of computation. The programmer is not required to explicitly specify the parallelism, as the details of how programs are scheduled and executed in a distributed environment are abstracted away by the run-time engine. XSLT provides a higher level programming model than many other approaches to web services composition; we explore its use here as a means of easing the task of orchestrating the interactions between services. In addition to the normal XSLT syntax, our system also supports programs written in XSLiTe, an alternative syntax we have developed which uses more concise representations of language constructs, increasing the ease of development, and bringing code readability closer to that of traditional programming languages. Our goal is to ease the construction of applications based on web services composition, such as those used in eScience and other fields in which service oriented architectures are prominent.Peter M. Kelly, Paul D. Coddington, Andrew L. Wendelbor

Using ontologies to support customisation and maintain interoperability in distributed information systems with application to the Domain Name System

©2006 IEEE. Personal use of this material is permitted. However, permission to reprint/republish this material for advertising or promotional purposes or for creating new collective works for resale or redistribution to servers or lists, or to reuse any copyrighted component of this work in other works must be obtained from the IEEE.Global distributed systems must be standards-based to allow interoperability between all of their components. While this guarantees interoperability, it often causes local inflexibility and an inability to adapt to specialised local requirements. We show how local flexibility and global consistency can coexist by changing the way that we represent these systems. The proven technologies already in use in the Semantic Web, to support and interpret metadata annotation, provide a well-tested starting point. We can use OWL ontologies and RDF to describe distributed systems using a knowledge-based approach. This allows us to maintain separate local and global operational spaces which, in turn, gives us local flexibility and global consistency. The annotated and well-defined data is better structured, more easily maintained and less prone to errors since its purpose can be clearly determined prior to use. To illustrate the application of our approach in distributed systems, we present our implementation of an ontologically-based Domain Name System (DNS) server and client. We also present performance figures to demonstrate that the use of this approach does not add significant overhead to system performance.Nickolas J. G. Falkner, Paul D. Coddington, Andrew L. Wendelbor

Bridging the gap between the semantic web and existing network services

©2006 IEEE. Personal use of this material is permitted. However, permission to reprint/republish this material for advertising or promotional purposes or for creating new collective works for resale or redistribution to servers or lists, or to reuse any copyrighted component of this work in other works must be obtained from the IEEE.This paper presents an overview of a mechanism for bridging the gaps between the Semantic Web data and services, and existing network-based services that are not semantically-annotated or do not meet the requirements of Semantic Web-based applications. The Semantic Web is a relatively new set of technologies that mutually interoperate well but often require mediation, translation or wrapping to interoperate with existing network-based services. Seen as an extension of network-based services and the WWW, the Semantic Web constitutes an expanding system that can require significant effort to integrate and develop services while still providing seamless service to users. New components in a system must interoperate with the existing components and their use of protocols and shared data must be structurally and semantically equivalent. The new system must continue to meet the original system requirements as well as providing the new features or facilities. We propose a new model of network services using a knowledge-based approach that defines services and their data in terms of an ontology that can be shared with other components.Nickolas J. G. Falkner, Paul D. Coddington, Andrew L. Wendelbor

Optimising performance in network-based information systems: Virtual organisations and customised views

©2006 IEEE. Personal use of this material is permitted. However, permission to reprint/republish this material for advertising or promotional purposes or for creating new collective works for resale or redistribution to servers or lists, or to reuse any copyrighted component of this work in other works must be obtained from the IEEE.Network-based information systems use well-defined standards to ensure interoperability and also have a tightly coupled relationship between their internal data representation and the external network representation. Virtual organisations (VOs), where members share a problem-solving purpose rather than a location-based or formal organisation, constitute an environment where user requirements may not be met by these standards. A virtual organisation has no formal body to manage change requests for these standards so the user requirements cannot be met. We show how the decoupling of the internal and external representations, through the use of ontologies, can enhance the operation of these systems by enabling flexibility and extensibility. We illustrate this by demonstrating a system that implements and enhances the Domain Name System, a global network-based information system. Migrating an existing system to a decoupled, knowledge-driven system is neither simple nor effortless but can provide significant benefits.Nickolas J. G. Falkner, Paul D. Coddington, Andrew L. Wendelbor

Compilation of XSLT into dataflow graphs for web service composition

Copyright © 2006 IEEEOur current research into programming models for parallel Web services composition is targeted at providing mechanisms for obtaining higher throughput for large scale compute and data intensive programs that delegate part of their computation to services, and making it easier to develop such applications. The ability to invoke multiple service calls at one time on different machines enables different portions of the program to be executed concurrently. We are addressing this through an implementation of an existing functional language, XSLT. Our implementation uses a dataflow execution model, and includes a compiler to build dataflow graphs from XSLT source code. This paper describes the execution model used to obtain parallelism and compose Web services, as well as the compilation process used to create the dataflow graphs. Our aim with this paper is to present the design of our system and demonstrate that XSLT provides a suitable model for distributed execution and parallel composition of Web services.Peter M. Kelly, Paul D. Coddington, and Andrew L. Wendelbor

The PAGIS Grid application environment

The original publication can be found at www.springerlink.comAlthough current programming models provide adequate performance, many prove inadequate to support the effective development of efficient Grid applications. Many of the hard issues, such as the dynamic nature of the Grid environment, are left to the programmer. We are developing a programming model that incorporates a familiar, formal computational model and a reflective interface. The programming model, called PAGIS, provides a desirable abstract computer with an interface to introduce and customize Grid functionality. Using PAGIS, an application programmer constructs applications that are implicitly parallel and distributed transparently. This paper describes the basic components of the PAGIS framework for constructing and executing applications, and the reflective techniques to customize applications for computation on the Grid.Darren Webb and Andrew L. Wendelbor