POJO Mojo

http://www.devx.com/Java/Article/32603

This article covers my basic thinking on how to keep transient data out of the database. I do believe that domain data will, for the forseeable future, belong in the database. But I simultaneously believe that transient data doesn't belong there. In the article, we avoid talking about a particular product and instead talk about the concepts and what it will take to simultaneously deliver the value of stateless while coding to a stateful model. I hope people find it worth the read.

We are doing a pretty kewl Webex on 10/25 where we show how to build the Master-Worker pattern using standard JDK1.5. Learn how to cluster it at runtime using DSO. There is also a real world app that implements a parallel web spider (much like Google might have done it in Java) using this approach. The neatest thing is all the source code to the implementation is available under BSD license for people to tweak and use as they see fit.

Attend the webinar and learn to operate / scale this reliable work-management system.

It is truly amazing what Open Source and the Java community in general have done for accelerating the rate of innovation in the enterprise software space. Taylor blogs about a really kewl application he wrote in a few minutes that implements something like Apple Stickies but on the Web.

A scant 5 years ago, I would have tried to build this using Java Applets in the browser for the GUI. It would have then used proprietary TPC/IP-based protocol (or HTTP) to send stickies back and forth to the central server. And, most importantly, it would have made those stickies durable / reliable via straight JDBC to a relational database. I have written such apps in the past 5 years. This prototype, with the exact same features and functions Taylor's app has, would have taken me 2 weeks to stabilize. And it would have been an applet which would not have worked well on all platforms.

Taylor built a flash app w/ OpenLaszlo.
He used SOAP for his client / server protocol via XFire.
And he made a clustered and restartable server by using our own DSO product.

Everything was POJO, soup-to-nuts. The state of the developer world is definitely improving.

Traditional approaches to session clustering incur a significant performance hit due to the overhead of serializing objects. Terracotta avoids serialization and instead clusters by replicating only field-level changes to objects and additionally only replicating changes out to the application nodes as the changes are requested.

In our most recent performance tests, 6 Tomcat nodes clustered with Terracotta Sessions sustained over 7,000 TPS compared to about 2,000 TPS for 6 nodes clustered with Tomcat's built-in "Pooled Mode" clustering. For the detals, see the Terracotta & Tomcat Sessions white paper at: http://www.terracottatech.com/documentation.shtml