Fundamentally, the JBoss architecture consists of the JMX MBean server, the microkernel, and a set of pluggable component services - the MBeans. This makes it easy to assemble different configurations and gives you the flexibility to tailor them to meet your requirements.
You don’t have to run a large, monolithic server all the time; you can remove the components you don’t need (which can also reduce the server startup time considerably) and you can also integrate additional services into JBoss by writing your own MBeans. You certainly do not need to do this to be able to run standard J2EE applications though.
You don’t need a detailed understanding of JMX to use JBoss, but it’s worth keeping a picture of this basic architecture in mind as it is central to the way JBoss works.
The JBoss Enterprise Application Platform ships with four different server configurations. Within the jboss-4.2.2.GA/server directory, you will find four subdirectories: minimal, default, production and all - one for each server configuration. Each of these configurations provide a different set of services. The default configuration is the one used if you don’t specify another one when starting up the server.
has a minimal configuration—the bare minimum services required to start JBoss. It starts the logging service, a JNDI server and a URL deployment scanner to find new deployments. This is what you would use if you want to use JMX/JBoss to start your own services without any other J2EE technologies. This is just the bare server. There is no web container, no EJB or JMS support. This is not a J2EE 1.4 compatible configuration.
is a base J2EE 1.4 server profile containing a default set of services. It has the most frequently used services required to deploy a J2EE application. It does not include the JAXR service, the IIOP service, or any of the clustering services.
The all configuration starts all the available services. This includes the RMI/IIOP and clustering services, which aren’t loaded in the default configuration.
If you want to know which services are configured in each of these instances, look at the jboss-service.xml file in the jboss-4.2.2.GA/server/<instance-name>/conf/ directory and also the configuration files in the jboss-4.2.2.GA/server/<instance-name>/deploy directory.
[usr@localhost jboss-4.2.2.GA]$ls server/default/conf
jbossjta-properties.xml jboss-service.xml props xmdesc
jboss-log4j.xml jndi.properties standardjbosscmp-jdbc.xml
jboss-minimal.xml login-config.xml standardjboss.xml
The default configuration is the one used if you don’t specify another one when starting up the server.
To start the server using an alternate configuration refer to Section 1.1.2.2, “Start the Server With Alternate Configuration”.