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)
Now that the WS-* specifications have become more mature, and SOA is becoming
the new architectural pattern for enterprise infrastructures, there are new
and unique architectural challenges that need to be addressed in order to
fully enjoy the capabilities SOA provides.
In order to fully exploit the interoperability that advanced Web Services
provide, a SOA infrastructure must support operational flexibility, a
heterogeneous application environment, scalability to support global
deployment, and the ability to be managed and monitored from a central point.
The enterprise service b... (more)
The past several years have seen some significant technology trends, such as
service-oriented architecture (SOA), enterprise application integration
(EAI), business-to-business (B2B), and Web services. These technologies have
attempted to address the challenges of improving the results and increasing
the value of integrated business processes, and have garnered the widespread
attention of IT leaders, vendors, and industry analysts. The enterprise
service bus (ESB) draws the best traits from these and other technology
trends to form a new architecture for integration. The ESB conc... (more)
Since releasing my latest book, Enterprise Service Bus (O'Reilly Media,
2004), I have been doing a fair amount of visiting corporations, conducting
seminars, and generally discussing with enterprise architects the subject of
enterprise service-oriented architecture (SOA) and how an enterprise service
bus (ESB) backbone can be leveraged to provide a framework for an enterprise
SOA. Along the way, I have been asked many questions about the nature of an
ESB. I have also fended off some misconceptions that have been growing in the
general IT population regarding what an ESB is and wh... (more)
The notion of guaranteed delivery of Java Message Service messages has been
lightly touched on in other recently published articles on JMS. But what
really makes a JMS message "guaranteed"? Should you just take it on faith, or
would you like to know what's behind it?
This article answers these questions via a detailed discussion of message
persistence, internal acknowledgment rules, and message redelivery. Using
excerpts condensed from the book we coauthored, Java Message Service, we'll
explain how JMS guaranteed messaging works - including once-and-only-once
delivery semantics,... (more)