- The basic administrative unit for a WLS is called a DOMAIN. Its just a logical unit.
- A domain is a logically related group of WebLogic Server resources that you manage as a unit.
- Each Domain includes only one instance of weblogic server called ADMINSTRATION SERVER. Admin server is the SPOC for all instances running on that domain and for system administration.
- Domain may also include additional WLS instances called MANAGED SERVERS. Within a domain some or all of the Managed Servers may be part of the cluster.
- A Managed Server can also function as a virtual host.
- A CLUSTER is a group of WebLogic Server instances that work together to provide scalability and high-availability for applications.
- A Managed Server in a cluster can act as a backup for services such as JMS and JTA that are hosted on another server instance in the cluster.
- All applications are also deployed and managed as part of a domain.
- There are two startup modes available for domains, i.e. DEVELOPMENT or PRODUCTION.
- As the name suggests,development mode is used while developing applications. Development mode uses a relaxed security configuration and has auto-deploy option for applications deployment.
- Production mode used when application is running in its final form.
- Startup mode details are stored in config.xml file
