JBoss in OS X Server

OS X Server version 10.3 includes JBoss version 3.2.2RC2. To provide a high level of availability, OS X Server includes a “watchdog” process that ensures that the application server is always running (if you turn on the application server in Server Admin). If the application server freezes or crashes, the daemon restarts it automatically.

In addition, OS X Server offers load balancing and session failover through Apache and JBoss:

• Apache, coupled with the mod_jk plug-in, provides HTTP load balancing with session affinity (sticky sessions) and connects to JBoss instances through AJP connectors.

• JBoss offers session failover through HTTP session state replication in the cluster configuration.

• JBoss also provides load balancing for enterprise beans, including failover for stateful session beans, and support for session affinity.

In OS X Server, JBoss is configured to use Tomcat (using the AJP connector) as its web server and servlet container. In addition, HTTP and HTTPS (through port 8443) are enabled by default.

You can manage the application server from the Server Admin application. This provides you with a simple way to start, stop, and monitor the application server. You can use the command line, if you prefer.

OS X Server includes two applications that allow you to deploy applications on JBoss and monitor their performance. They are the JBoss deployment tool and the JBoss management tool.

The deployment tool allows you to configure an application or an application component so that, for example, it accesses the appropriate data sources and database tables when it’s run. This is how application developers decouple business logic from the database engine that is used to persist data. That way, you can use the database engine that meets your needs and not the one the developer used while developing the application. For details on the deployment tool, see Configuring Applications.

The management tool lets you administer the local (running on the computer you are logged in to) application server, and monitor local and remote (running on a computer in the local network) application servers. As part of administering an application server, you may start and stop services, configure services, deploy applications, and add data sources, queues, and topics. When monitoring an application server, the management tool lets you access the statistics provided by the resources and services running on it. For example, a service may indicate its name, its purpose, and when it was started. For more information on the management tool, see Administering Application Servers.

Three Deployment Configurations

In OS X Server, all the JBoss configurable settings are set up for maximum J2EE compliance. There are three standard deployment configurations in JBoss for OS X Server:

• The development configuration offers increased logging and also consults schema documents. As a result, an application is not deployed when the configuration files do not adhere to their respective schemas.

• The standalone configuration is set up for high performance on a single server.

• The cluster configuration is optimized for high performance on a cluster of servers. This includes load balancing as well as session replication among stateful session beans and HTTP sessions.