Martin P. Nally

Toward a programming model for service-oriented computing

The service oriented paradigm is, at its core, a model of distributed software components, built around the idea of multi-protocol interoperability and standardized component contracts. The Web Services Interoperability (WS-I) profiles provide standards for runtime interoperability, and the Web Services Description Language (WSDL) and WS-Policy define service contracts that support interoperability between developer tools. A major goal of Service Oriented Architectures (SOAs) is to enable an abstraction layer that integrates and bridges over platform and implementation technology differences, effectively providing a universal business software component and integration framework. Achieving a complete solution requires a portable component model and well-defined patterns for components types. This paper examines the main requirements for a SOA programming model and identifies its most relevant characteristics. In line with SOA’s goals, such model must allow a broad community of users (including non-programmers) to create service-oriented applications by instantiating, using, assembling and customizing different component types that match the user’s goals, skills, and conceptual framework. Moreover, these component types must be portable and interoperable between multiple different vendors’ runtimes.

Rational software architect: a tool for domain-specific modeling

Rational Software Architect (RSA), the latest generation Rational® modeling tool, is based on EclipseTM Modeling Framework (EMF) technology. RSA offers all the important features of the previous generation of Rational modeling tools, while supporting a much wider range of model formats. RSA diagrams can be used in editing and displaying models derived from any EMF-based metamodel. The combination of RSA and EMF provides a powerful capability for integrating domain-specific languages (DSLs) with UML® in a single toolset. This paper describes how RSA and EMF provide these capabilities and explores some of the ways that IBM is currently exploiting them.

Application servers: one size fits all ... not?

In the beginning there was machine language, followed by assembly language, formula translation, and eventually procedural programming, to organize the chaos. And then objects were introduced, to hide information. Soon Client/Server and multi-tier applications were conceived to separate data concerns from business logic concerns and user interface concerns. Later, these objects were distributed geographically to optimize hardware resources. And now, we have application servers, to simplify scaling up a system for large volumes, improved response times, impeccable reliability, and high availability. Application servers house the business logic, operating on data from a different server, and responding to requests from any source. But these Application Servers come in all shapes, flavors, and sizes. What is a developer to do? This panel will explore issues comparing application server technologies and questions about their appropriate use in different contexts.

Application servers: virtualizing location, resources, memory, users and threads for business applications and web applications

Application servers provide an environment for running business and web applications. By virtualizing threads, data and processing resources, memory and users, they provide the simplifying illusion for the programmer that the application is interacting with a single user, is running alone on the server, and is the sole user of resources, while allowing an efficient realization that scales with the number of users, and available hardware. They also provide a virtual environment where security enforcement and demarcation of transaction boundaries are automatic. This talk will describe some of the major features of modern application servers and show how concepts of virtualization are fundamental to their design and realization.