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Posted by editor on December 11, 2007 at 7:45 AM PST

JXTA-powered clustering for GlassFish

Is JXTA the secret sauce in some of the coolest Java stuff? We keep up with developments from the JXTA community and its various projects, but it's deceptively easy to focus just on the library and not on what people are doing with it. To wit, two of the projects on the page today are JXTA-powered, but don't make a big point of it -- they're content to focus on the value they provide rather than what bits they use to do so.

And maybe that's as it should be, but it's worth taking stock of the fact that lots of people are using JXTA for a variety of projects, even while a lot of developers have probably overlooked it since its big launch a number of years ago. Like Jini, it has loyal adherents who talk it up, and better yet, put it to use to provide effective self-networking.

The first JXTA-powered item on the page today is our latest Feature Article, Clustering with the Shoal Framework by Diego Naya and Juan Pedro Danculovic:

Shoal is an open
source, Java-based generic clustering framework. It can be used in
your applications to add clustering functionalities like load
balancing, fault tolerance, or both. Applications using Shoal can
share data, communicate via messages with other cluster nodes across the
network, and notify of relevant events like the joining,
shutdown, and failure of a node or group of nodes. You can take
appropriate measures and perform monitoring tasks when these events
occur; Shoal forwards a signal to your code to track these

Shoal is the clustering framework used by the "">Glassfish project to
implement its application server clustering. One of the benefits to
your application is that Shoal abstracts away network details and
the network communication API. Under the hood, the default group
communication provider uses "">JXTA for peer-to-peer reliability
and scalability.

Join Diego and Juan Pedro as they show how to directly access the Shoal API to put clustering to work in your own application, whether or not you're using GlassFish or even EE. And as your nodes come online and work with each other, enjoy JXTA doing all the peering work for you.

JXTA also powers the networked concept-sharing features of the
Aieon-F project, which tops the Java Today section. This meta-information framework project has just announced its emergence from the incubator. "Aieon-F is a meta-information framework. Basically it defines
units of information called concepts,
or aieons when they
point to something tangible, such as web links, documents, mp3 files
and so on. Aieons can also define relationships with other aieons,
and this way a knowledge base can be constructed that ties together
unrelated information." Saight, a social bookmarking application based on Aieon-F, is also available for download as a beta version.

The OpenJDK project recently posted minutes from the August 23, 2007 meeting, in which the group discussed the OpenJDK Community TCK License (PDF, 128 KB), which had been announced two weeks prior. "The meeting was essentially a long question-and-answer session, with no agreed resolutions, so these minutes are structured in a Q&A format in the following sections: License-application process, License eligibility, Running the TCK, Certifying a platform implementation, Confidentiality, Miscellaneous."

Build processes in Java haven't evolved much since the introduction of Ant or Maven. With the ability to use scripting languages like Groovy and JRuby on the JVM, the power of a full language can be brought to bear on the build process. In the ONJava article Introducing Raven: An Elegant Build for Java, Matthieu Riou discusses Raven, a build system for Java that uses JRuby.

In today's Weblogs, Simon Morris makes a nice Douglas Adams reference in introducing Your Plastic Pal Who's Fun to be With.
"Like many people I've been spending some of my free time over the last couple of weeks playing with Android. Google's departure from traditional mobile Java has caused a flurry of comment, but politics aside what is the new platform like to develop for?"

Sivasubramanian Muthusamy offers an interesting allegory in
anycar anylane anywhere drivers, a story that begins:
"Long long ago, so long ago that no body could say how long ago, thousands of people from China, Rome, France and India climbed up a mountain somewhere near Cripple Creek, Colorado and built houses to live in and lived there..."

Finally, Petar Tahchiev works through issues with
Bluetooth remote control.
"Hey everybody, I had lots of questions about my cell-phone bluetooth remote control when I was at the OpenFest and ApacheCON conferences."

In today's Forums,
.NET convert chris55 seeks
Reusable Visual Web Components in Java.
"I recently made the switch (more like ran away) from .NET to Java. I simply got tired of the M$ framework/IDE upgrade treadmill. I am working on Ubuntu 7.10 with NetBeans 6 (+ICEfaces), JDK 1.6, J2EE 5, TomCat 5.5, Glassfish 2 and MySql 5. My question relates to building reusable visual web components using NetBeans. I reviewed tutorials on JSF and Facelets but remain alittle confused... Does NetBeans support a framework (Facelets/JSFTemplating) to visually build a web component (+ interfaces/delegates/data source plumbing/etc.) and visually drop it within a JSP or another web component? This feature exists in MS Visual Studio (2002+) as usercontrols/web controls that can be dropped onto an ASPX or another usercontrol/web control."

Meanwhile, the curiously-named csharpdotcom is looking to build a
Hit counter.
"I would be very grateful to know how to implement hit counters with JSF. I am putting together a website with three main pages, the first is basically an index page, then depending on which of two links are followed, you are taken to one of two pages containing large forms which have to be submitted. I would like to put a hit counter on all three pages, and possibly separate counters that record how many times the "submit" button has been clicked."

Finally, qu0ll is repeating a thusfar-unanswered call for help in
Re: Using GlassFish as an RMI server.
"...hmm, no replies... surely someone out there can help me! Hasn't anyone developed a module for GlassFish or integrated RMI with GlassFish? Any help will be greatly appreciated."

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JXTA-powered clustering for GlassFish