Platform Independent Metamodel Research Articles

A Platform Independent Access Control Metamodel for Web Services

Web services provide platform independent communication through an XML-based standard family. The major software vendors released their own SOA products implementing these standards. However, the configuration of the WS-* protocols differs from product to product. Matching these configurations between different products can be a very tedious task. Security protocols are among the most complicated protocols to configure, especially if access control is also required. Although the XACML standard aims to solve this task, its rules and policies described in XML are not very user friendly, and XACML has a very poor support in the major SOA products. Therefore, we have developed a platform independent metamodel for describing distributed systems of web services. From models described in this metamodel the platform specific configurations and program codes can be easily generated for the various SOA products, increasing the productivity of the development. This article introduces an access control extension to this metamodel.

A Metamodel for the Web Services Standards

Web services provide distributed communication in a platform independent way. The WS-* standards define how middleware aspects (security, reliability, transactions, etc.) can be realized through web services. Although the WS-Policy standard family can be used to configure the various WS-* protocols, they are very hard to construct and to maintain manually. In addition, most SOA products and Grid systems implementing these standards provide their own methods for configuring these protocols, making it very difficult to match the various configuration options of different products. This fact inspired us to propose a platform independent metamodel for describing distributed systems of web services including the most important WS-* standards. The present article defines the full metamodel, it specifies the corresponding programming language formally, and it shows the productivity of the framework built around the metamodel through real-life examples. The framework is capable of generating product specific configuration files and source codes, resulting in directly interoperable applications even between different SOA products. The framework could also promote interoperability with Grid systems built on WS-* protocols.

A model driven development approach based on a reference model for predicting disruptive events in a supply process

Due to the impossibility of predicting with certainty the occurrence of disruptive events, buffers defined to obtain a robust schedule could not absorb all the changes. Then, local modifications of the schedule are usually performed to avoid a new planning task. For this task, obtaining disruptive event information in advance can help to make better decisions. As a result, ability to predict disruptive events that affect the execution of the supply process an order represents is required. With the objective of satisfying this requirement, this work proposes a model driven development approach based on a reference model to automate the generation of the monitoring model of a supply process able to anticipate the occurrence of a disruptive event by monitoring variables that can explain it.The approach proposes both a reference model to represent the monitoring model independently of the implementation platform, and a specific model to represent the monitoring model with the particular language of the implementation platform. An engine based on transformation rules allows automating the generation of a platform dependent monitoring model from an instance of a platform independent metamodel. The monitoring component of a SCEM system has been developed, which implements the transformation engine as a Bayesian Network model, and uses an appropriate tool to execute it. For an empirical validation of the model three case studies are presented.

A platform-independent metamodel for multiagent systems

Various agent-oriented methodologies and metamodels exist to design and develop multiagent systems (MAS) in an abstract manner. Frequently, these frameworks specialise on particular parts of the MA...

An MDA approach to Access Control Specifications Using MOF and UML Profiles

We present a Model Driven Development (MDD) approach to the development of access control policies for distributed systems. The models are expressed as Meta-Object Facility (MOF) models enriched by Unified Modeling Language (UML) profiles. The view-based access control model is used as an example, for which we present a platform independent meta-model and platform specific meta-models for the Java 2 Platform, Enterprise Edition (J2EE). A management application is used to build instance models for the platform independent and platform specific meta-models, respectively.We present in this paper how the platform independent models can be used to generate the platform specific models, and how the meta-models can be used to generate the models for the specific application. Finally, the platform specific models are used to generate the security policy to be deployed in the security infrastructure.We show how consistence requirements can be verified formally by using category-based graph transformations.