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From the vice president and chief technologist for SOA at Oracle Corporation

Dave Chappell

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Top Stories by Dave Chappell

The Open Services Gateway Initiative (OSGi) Alliance is working to realize the vision of a "universal middleware" that will address issues such as application packaging, versioning, deployment, publication, and discovery. In this article we'll examine the need for the kind of container model provided by the OSGi, outline the capabilities it would provide, and discuss its relationship to complementary technologies such as SOA, SCA, and Spring. Enterprise software is often composed of large amounts of complex interdependent logic that makes it hard to adapt readily to changes in requirements from the business. You can enable this kind of agility by following a Service Oriented Architecture (SOA) pattern that refactors a system into application modules grouped by business functions that expose their public functionality as services (interfaces). For example, a customer... (more)

Benchmarking JMS-Based E-Business Messaging Providers

Benchmarking any distributed computing middleware product is a complex task. Knowing how well a distributed infrastructure will perform under heavy load with a large number of concurrently connected users is a key factor in planning a development and deployment strategy. With the advent of Java Message Service (JMS) as the standard for a global class middleware infrastructure, development organizations can enjoy the luxury of building distributed applications using a common set of APIs and message delivery semantics. At the same time they can pick and choose from a variety of JM... (more)

Asynchronous Web Services

In a recent "Strategic Planning" research note, Gartner issued a prediction that "by 2004, more than 25 percent of all standard Web services traffic will be asynchronous...." and "by 2006, more than 40 percent of the standard Web services traffic will be asynchronous." One of the cornerstones of Web services interoperability is the SOAP (Simple Object Access Protocol). SOAP began simply as a way of performing a synchronous RPC (Remote Procedure Call) across the Internet over an HTTP connection. However, the current "owners" of SOAP ­ the XML Protocol WG at the W3C ­ have been t... (more)

Message-Centric Web Services vs RPC-Style Web Services

Message-centric vs RPC-style Web services is a long-standing debate and bone of contention regarding the proper use of Web services technologies. Early renditions of SOAP and XML-RPC were all about providing RPC-style interactions...in fact, that's all that was supported, so there really wasn't much choice in the matter. RPC-style interfaces have their advantages: immediate gratification of request/response, and a programming model whereby remote procedures are exposed in a way that mimics the underlying object architecture of the applications concerned, allowing a developer to ... (more)

Will the Real Reliable Messaging Please Stand Up? Is it WS-Reliability, WS-ReliableMessaging, or WS-ReliableConundrum?

Open standards for reliable Web services messaging, such as WS-Reliability, can provide the missing link to bridge the gap between organizations and help make Web services a truly enterprise-capable technology for standards-based systems integration, says Web Services Journal technical editor David Chappell. Along with security, reliable asynchronous communications has been one of the gaping holes in today's Web services architecture. Lack of reliability, due to the inherent nature of using SOAP over protocols such as HTTP, is one of the biggest obstacles to the adoption of Web s... (more)