Farouk Toumani

Developing adapters for web services integration

The push toward business process automation has generated the need for integrating different enterprise applications involved in such processes. The typical approach to integration and to process automation is based on the use of adapters and message brokers. The need for adapters in Web services mainly comes from two sources: one is the heterogeneity at the higher levels of the interoperability stack, and the other is the high number of clients, each of which can support different interfaces and protocols, thereby generating the need for providing multiple interfaces to the same service. In this paper, we characterize the problem of adaptation of web services by identifying and classifying different kinds of adaptation requirements. Then, we focus on business protocol adapters, and we classify the different ways in which two protocols may differ. Next, we propose a methodology for developing adapters in Web services, based on the use of mismatch patterns and service composition technologies.

On automating Web services discovery

Abstract.One of the challenging problems that Web service technology faces is the ability to effectively discover services based on their capabilities. We present an approach to tackling this problem in the context of description logics (DLs). We formalize service discovery as a new instance of the problem of rewriting concepts using terminologies. We call this new instance the best covering problem. We provide a formalization of the best covering problem in the framework of DL-based ontologies and propose a hypergraph-based algorithm to effectively compute best covers of a given request. We propose a novel matchmaking algorithm that takes as input a service request (or query) Q and an ontology

Representing, analysing and managing web service protocols

\mathcal{T}

Web service conversation modeling: a cornerstone for e-business automation

of services and finds a set of services called a “best cover” of Q whose descriptions contain as much common information with Q as possible and as little extra information with respect to Q as possible. We have implemented the proposed discovery technique and used the developed prototype in the context of the Multilingual Knowledge Based European Electronic Marketplace (MKBEEM) project.

Request rewriting-based web service discovery

In the area of Web services and service-oriented architectures, business protocols are rapidly gaining importance and mindshare as a necessary part of Web service descriptions. Their immediate benefit is that they provide developers with information on how to write clients that can correctly interact with a given service or with a set of services. In addition, once protocols become an accepted practice and service descriptions become endowed with protocol information, the middleware can be significantly extended to better support service development, binding, and execution in a number of ways, considerably simplifying the whole service life-cycle. This paper discusses the different ways in which the middleware can leverage protocol descriptions, and focuses in particular on the notions of protocol compatibility, equivalence, and replaceability. They characterize whether two services can interact based on their protocol definition, whether a service can replace another in general or when interacting with specific clients, and which are the set of possible interactions among two services.

Web services interoperability specifications

Web services are emerging as a promising technology for effectively automating interorganizational interactions. However, despite the growing interest, several issues remain to be addressed to provide Web services with benefits similar to what traditional middleware brings to intraorganizational application integration. We identify a framework that builds on current standards to help developers define extended service models and richer Web service abstractions. The frameworks main feature is a conversation metamodel derived from our analysis of e-commerce portal sites.

Model-Driven Web Service Development

One of the challenging problems that Web service technology faces is the ability to effectively discover services based on their capabilities. We present an approach to tackle this problem in the context of DAML-S ontologies of services. The proposed approach enables to select the combinations of Web services that best match a given request Q and effectively computes the extra information with respect to Q (e.g., the information required by a service request but not provided by any existing service). We study the reasoning problem associated with such a matching process and propose an algorithm derived from hypergraphs theory.

Using Queries to Improve Database Reverse Engineering

A proposed conceptual framework for analyzing Web services interoperability issues provides a context for studying existing standards and specifications and for identifying new opportunities to provide automated support, for this technology. Web services are becoming the technology of choice for realizing service-oriented architectures (SOAs). Web services simplify interoperability and, therefore, application integration. They provide a means for wrapping existing applications so developers can access them through standard languages and protocols.

Conceptual modeling of web service conversations

Web services are emerging as a promising technology for the effective automation of inter-organizational interactions. However, despite the growing interest, several issues still need to be addressed to provide Web services with benefits similar to what traditional middleware brings to intra-organizational application integration. In this paper, we present a framework that supports the model-driven development of Web services. Specifically, we show how, starting from the external specifications of a Web service (e.g., interface and protocol specifications), we can support the generation of extensible service implementation templates as well as of complete (executable) service specifications, thereby considerably simplifying the service development work.

Analysis and Management of Web Service Protocols

This paper describes a technique that supports Extended Entity-Relationship (EER) schema extraction from an operating relational database. In this reverse engineering context, the two major decisions that have to be taken are the assumptions on the initial schema and where data semantic is extracted from. Original aspects of our method are manifold. First, it is based on realistic assumptions, e.g., there is no constraints on the uniqueness of the attribute names. Second, the dependencies between the attributes are not supposed to be known a priori. The method starts from the database schema as stored in the DBMS dictionary, i.e., the relation names, the attribute names and their basic characteristics (uniqueness of value, not null values). Finally, semantics extraction is supported by available queries analysis. It is shown how specific kinds of query can help to build an EER schema including is-a relationships and aggregates.