Weblogic Suite, currently in version 11g (Oracle has announced possibly version 12c for this summer) is the base platform for all the applications that Oracle includes under the concept of Fusion Middleware.
Everything indicates that for version 12c the Fusion family will be even more extensive in Oracle’s desire to integrate all its applications with each other and therefore the need to control or use Weblogic Suite will be even greater.
In this blog we are going to describe some concepts of WebLogic Suite in order to understand this tool a little more.
Domain
A domain in WebLogic is a container or grouper of one or more instances (servers). It may contain servers (e.g. SOA Server, UCM Server) or server clusters.
It is very important that all instances under the same domain have the same version (only the first two digits e.g. 10.3, the other digits do not matter).
We can say that a domain is basic and essential in any Weblogic Suite installation. Its configuration is simple for both Linux and Windows OS.
Servers
A server in Weblogic is an installed instance that contains its own Java virtual machine and therefore can run independently of the other existing servers in the same domain.
The advantage of each server having its own virtual machine lies in the fact that you can stop/start/update a specific server without affecting the rest of the servers.
WebLogic manages 2 types of servers:
- Administration Server (Administration Server)
- Management Server (Managed Servers)
The Administration Server, as the name itself indicates, serves to manage all the components available/installed under a WebLogic Suite.
You are only allowed to have a single Administration Server per WebLogic domain.
In Production, it is recommended that the Administration Server be installed separately on an independent physical server.
As its purpose is to manage/administer a domain to deploy, start up, stop instances and other types of configurations it can be stopped once the management servers are deployed and running.
Management Servers are independent instances under the same domain.
Examples: SOA Server, UCM Server, Identified Management Server etc.
Cluster
A cluster is a set of servers (instances) that work synchronously.
The servers in a cluster must be under the same domain.
For a cluster to be configured and function correctly, 2 objectives must be met:
- All servers in the same cluster must use the same java virtual machine (currently Oracle has 2 java virtual machines HotsPot and JRockit with the intention for the future to merge them into a single open source java virtual machine OpenJdk)
- The version of the installed applications that are part of a cluster must have the same version (unlike the same version required for the member servers of a domain, for the servers that are part of a cluster the version must match in the first 3 digits or even the first 4 digits e.g. 10.3.5.1)
Node Manager
A node is made up of one or more Managed Servers and is mainly used to start/shut down one or all associated servers remotely.
A node is not associated with a domain.
Machine
A machine in WebLogic physically identifies a server. Each machine can contain one or more installed instances (management servers).
Later we will explain in detail how each of the concepts in this post are correctly configured.
