Integrating heterogeneous web service styles with flexible semantic web services groundings

Semantic web services are touted as a means to integrate web services inside and outside the enterprise, but while current semantic web service frameworks— including OWL-S [1], SA-WSDL, and WSMO 1 [2]—assume a homogeneous ecosystem of SOAP services and XML serialisations, growing numbers of real services are implemented using XML-RPC and RESTful interfaces, and non-XML serialisations like JSON. 2 Semantic services platforms based on OWL-S and WSMO use XML mapping languages to translate between an XML serialisation of the ontology data and the on-the-wire messages exchanged with the web service, a process referred to as grounding. This XML mapping approach suffers from two problems: it cannot address the growing number of non-SOAP, non-XML services being deployed on the Web, and it requires the modeller creating the semantic web service descriptions to work with the serialisation of the service ontology and a syntactic mapping language, in addition to the knowledge representation language used for representing the semantic service ontologies and descriptions. Our approach draws the service’s interface into the ontology: we defin

Implementing fault tolerant applications using reflective object-oriented programming

Abstract: Shows how reflection and object-oriented programming can be used to ease the implementation of classical fault tolerance mechanisms in distributed applications. When the underlying runtime system does not provide fault tolerance transparently, classical approaches to implementing fault tolerance mechanisms often imply mixing functional programming with non-functional programming (e.g. error processing mechanisms). The use of reflection improves the transparency of fault tolerance mechanisms to the programmer and more generally provides a clearer separation between functional and non-functional programming. The implementations of some classical replication techniques using a reflective approach are presented in detail and illustrated by several examples, which have been prototyped on a network of Unix workstations. Lessons learnt from our experiments are drawn and future work is discussed

Grounding semantic web services with rules

Semantic web services achieve effects in the world through web services, so the connection to those services - the grounding - is of paramount importance. The established technique is to use XML-based translations between ontologies and the SOAP message formats of the services, but these mappings cannot address the growing number of non-SOAP services, and step outside the ontological world to describe the mapping. We present an approach which draws the service's interface into the ontology: we define ontology objects which represent the whole HTTP message, and use backward-chaining rules to translate between semantic service invocation instances and the HTTP messages passed to and from the service. We present a case study using Amazon's popular Simple Storage Service

Innervision and Innertext: Oral and Interpretive Modes of Storytelling Performance

"Within the past twenty years there has evolved a national--even, to a limited extent, an international--community of performers who position themselves under the sign of a self-conscious revival of traditional storytelling. Although their actual practices cover a wide range of performance conventions--from a variety of ethnic traditional storytelling styles, to standup comedy, to theatrical impersonation, to autobiographical performance art, to oral interpretation--these contemporary performers share in the invocation of ancient traditions and roles as a common signifying framework."--Introduction

Investigating web APIs on the World Wide Web

Abstract—The world of services on the Web, thus far limited to “classical ” Web services based on WSDL and SOAP, has been increasingly marked by the domination of Web APIs, characterised by their relative simplicity and their natural suitability for the Web. Currently, the development of Web APIs is rather autonomous, guided by no established standards or rules, and Web API documentation is commonly not based on an interface description language such as WSDL, but is rather given directly in HTML as part of a webpage. As a result, the use of Web APIs requires extensive manual effort and the wealth of existing work on supporting common service tasks, including discovery, composition and invocation, can hardly be reused or adapted to APIs. Before we can achieve a higher level of automation and can make any significant improvement to current practices and technologies, we need to reach a deeper understanding of these. Therefore, in this paper we present a thorough analysis of the current landscape of Web API forms and descriptions, which has up-to-date remained unexplored. We base our findings on manually examining a body of publicly available APIs and, as a result, provide conclusions about common description forms, output types, usage of API parameters, invocation support, level of reusability, API granularity and authentication details. The collected data provides a solid basis for identifying deficiencies and realising how we can overcome existing limitations. More importantly, our analysis can be used as a basis for devising common standards and guidelines for Web API development. Keywords-Web APIs, RESTful services, Web services I

Semantic web service automation with lightweight annotations

Web services, both RESTful and WSDL-based, are an increasingly important part of the Web. With the application of semantic technologies, we can achieve automation of the use of those services. In this paper, we present WSMO-Lite and MicroWSMO, two related lightweight approaches to semantic Web service description, evolved from the WSMO framework. WSMO-Lite uses SAWSDL to annotate WSDL-based services, whereas MicroWSMO uses the hRESTS microformat to annotate RESTful APIs and services. Both frameworks share an ontology for service semantics together with most of automation algorithms