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" Given that web service invocations are always remote across the internet, developing rigorous and responsive web service client applications has always been a challenge for architects and developers working with SOA. JAX-WS 2.0 comes with one effective solution to this problem: asynchronous web service invocation, with which a web service client may interact with a web service in a non-blocking, asynchronous approach. In this article, we will provide an exposition of this technology with examples built upon the reference implementation. Our examples utilize JDK 5.0, JAX-WS 2.0 reference implementation (RI), and Tomcat 5.5. JAX-WS 2.0 requires JAXP 1.3. To replace the JAXP 1.2 released with JDK 5.0 with this newer version, one approach is to download the JAXP 1.3 RI, and copy the endorsed directory under /lib of its installation home to %JAVA_HOME%/jre/lib. We need to copy the jaxp-api.jar of JAXP 1.3 RI to %JAVA_HOME%/jre/lib/endorsed as well. To make Tomcat 5.5 work with JAX-WS 2.0, readers need to copy all the .jar files under the /lib directory of the JAX-WS 2.0 RI installation to the %CATALINA_HOME%/shared/lib directory. As of this writing (in addition to Tomcat 5.5), Sun Java System Application Server 9.0, GlassFish, and Celtix also support JAX-WS 2.0. xFire is in the process of completing its implementation of this specification. Since asynchronous web service invocation in JAX-WS 2.0 is built upon the concurrent programming support in JDK 5.0 introduced with the java.util.concurrent package, we will start from there."

"Developing rigorous and responsive web service client applications has always been a challenge for architects and developers working with SOA. JAX-WS 2.0 comes with one effective solution to this problem: asynchronous web service invocation. In this article, we will provide an exposition of this technology with examples built upon the reference implementation. The JAX-WS programming model offers two models for invoking operations asynchronously - polling and callback. Both methods allow the client to continue processing while waiting for a response."

ECF is a framework for building distributed servers, applications, and tools. It provides a modular implementation of the OSGi 4.2 Remote Services standard, along with support for REST-based and SOAP-based remote services, and asynchronous messaging for remote services. See the ECF Wiki for examples, tutorials, other documentation, as well as plans and efforts currently underway for future releases.

There are many approaches available to scale PostgreSQL beyond running on a single server. An outline of the terminology and basic technologies involved is at High Availability and Load Balancing. There is a presentation covering some of these solutions. There is no one-size fits all replication software. You have to understand your requirements and how various approaches fit into that. For example, here are two extremes in the replication problem space: You have a few servers connected to a local network you want to always keep current for failover and load-balancing purposes. Here you would be considering solutions that are synchronous, eager, and therefore conflict-free. Your users take a local copy of the database with them on laptops when they leave the office, make changes while they are away, and need to merge those with the main database when they return. Here you'd want an asynchronous, lazy replication approach, and will be forced to consider how to handle conflicts in cases where the same record has been modified both on the master server and on a local copy. These are both database replication problems, but the best way to solve them is very different. And as you can see from these examples, replication has a lot of specific terminology that you'll have to understand to figure out what class of solution makes sense for your requirements. A great source for this background is in the Postgres-R Terms and Definitions for Database Replication. The main theoretical topic it doesn't mention is how to resolve conflict resolution in lazy replication cases like the laptop situation, which involves voting and similar schemes.

"Background processes in Eclipse RCP and Eclipse Plugins This article describes how to use the Job API in Eclipse RCP and Eclipse plugins to perform asynchronous tasks. It also discuss how to update the UI thread. This article is based on Eclipse 3.6 (Helios). "

"Errai is a framework for building GWT applications Errai offers a set of components for building rich web applications using The Google Web Toolkit. The framework provides a unified federation and RPC infrastructure with true, uniform, asynchronous messaging across the client and server."