a cup of java

First of all, I would like to thank whitelassiblog for bringing this to my notice. You can see his comment here on my post.

As I never did any JBoss clustering in my life, I searched (in fact “Googled“) for it. And I found a small & nice article on it.

What is the farm service ?

That is hot-deploying the application archive file (e.g., the EAR, WAR or SAR file) in the all/farm/ directory of any of the cluster members, will cause the application to be automatically duplicated across all nodes in the same cluster.

If node joins the cluster later, it will pull in all farm deployed applications in the cluster and deploy them locally at start-up time. If you delete the application from one of the running cluster server node’s farm/ folder, the application will be undeployed locally and then removed from all other cluster server nodes farm folder (triggers undeployment.) You should manually delete the application from the farm folder of any server node not currently connected to the cluster.

Read this article here: http://www.mastertheboss.com/en/jboss-application-server/146-jboss-farming-service.html

But in JBoss 5 this feature is not available.

Unfortunately this replacement for farming is not ready available for AS 5.0.0.GA. The Farm Service’s function of replicating deployment archives between file systems will not be maintained.

At the moment the easiest solution to deploy a JBoss application on JBoss AS 5 is creating a script which copies the file on all the “deploy” folder of your Nodes.

Hope this helps.

My friend Venu had a recent post in his blog on migrating from Jboss 4 to Jboss 5.

Our application runs on Jboss4.0.5 for almost 2.5 years now. One thing that was appealing me the most with Jboss5 was its proved performance wrt JBoss Messaging. We have been using JBossMQ for long.

The day wasn’t pleasant when i started exploring Jboss5. It threw all strange errors and Exceptions to a newbie like me at the outset. Ok.. After about 3/4th of a week was spent, i was gaining grip on the new beast Jboss5 (finally).

You should not be bewildered initially. I would like to mention few things i learnt the very hard way.

You can find the post here: http://venugopaal.wordpress.com/2009/02/02/jboss405-to-jboss-5ga/

Have a nice read. I hope this will be very helpful.

SOA – Service Oriented Architecture – is an architectural design pattern, where an application is developed as a set of logically & functionally separate and independent services. Each of these services can be implemented in any platform, programming language using any of the available technologies. These services can communicate with each other to fulfill their needs and can send & receive pieces of information from other services as well. One service can interact with more than one service to get the desired things done. SOA can be implemented using web services, since the protocols & standards of internet are very much platform & programming language independent. The main purpose of SOA is to reduce the coupling between the modules.

Requirements of SOA
1) We should make use of standards & protocols supported by most of the platforms since these services may be distributed among wide verity of them. (Means, there should be a standard and widely accepted mechanism for the services to talk with each other)
2) There should be a “clear & unambiguous” service interface syntax.
3) There should be a service registry mechanism to retrieve the suitable services.

SOA Building Blocks
Service provider: Provides a set of services to the requesting clients/services. The provider can restrict the services they offer as well as define the service scope to public or private. Public services can be accessed by anyone over the internet but the private services are restricted to certain clients. The service provider should register the interface & service access information with the service registry.

Service Broker/Service Registry: Provides the interface & service access information to any service requestors. The implementer can also decide the scope of the registry too.

Service requestor: It’s a web service client. The requester searches the service registry using different search methods to find a service entry and then binds to the corresponding service provider to get the things done.

Useful links
http://en.wikipedia.org/wiki/Service-oriented_architecture
http://webservices.xml.com/pub/a/ws/2003/09/30/soa.html
http://www.service-architecture.com/