Oracle Weblogic Server

We will now see how to set up a cluster in weblogic 10.3 but before that we need to have some concepts about the terms and terminology in weblogic.

WEblogic is an Enterprise J2EE Server which provides higher reliability,Availability, Scalability and Performance.

Few important terms in weblogic

A domain in a weblogic server is a group of instances and clusters under one single control.Domains contains a WebLogic Server instance called the Administration Server we also called in short it as admin server.This is the main place from where we control and manage all the resources in a domain. We also create our own weblogic instances called as managed server.We deploy our application in the managed server and from admin server we configure and monitor them.We have a terminology called cluster within a domain which is nothing but group of managed servers to provide increased scalability and reliability to the end users.Also we have node manager which is a process to start/stop and auto restart the managed server.so essentially our domain consist of one admin server, one or more managed server,one node manager and one or more cluster.

Again a server in weblogic can be a standalone server or it can be a part of a cluster.All Managed Servers in a cluster must reside in the same domain i.e. you cannot split a cluster over multiple domains.


If you have created multiple domains in weblogic, then each domain must point to its own database schema. You cannot share a configured resource or subsystem between domains. For example, if you create a JDBC data source in one domain, you cannot use it with a Managed Server or cluster in another domain.You must create a similar data source in the second domain.

When a Managed Server starts, it connects to the Administration Server to check the data maintained by the admin server.so whenever a configuration is changed the admin server sends the changed configuration to the managed servers.

Weblogic scripting tool(WLST)

WLST is a scripting language based in jython.It is a Scripting tool for administering a domain (create, configure, manage, monitor, deploy applications).We have a record feature in admin console of weblogic.This records the data in the form of wlst scripts.There are two modes of WLST script

1>Offline WLST
With offline WLST you can create a domain template,or create a domain based on existing template without connecting to the server.

2>Online WLST
WLST online is a Java Management Extensions (JMX) client.With online WLST you can connect to a running admin server,manage the configuration of a domain and check its performance data.


NOde Manager

Node Manager is a WebLogic Server utility that enables you to start, stop, and restart Administration Server and Managed Server instances from a remote location. It is not associated with a domain but with a machine.

Machine is nothing but a logical name for a computer to associate it with its managed server.

Again one important feature of weblogic is jrockit.It is developed to optimize performance on Windows and Linux only.It is BEA's version of JVM.YOu can also use SUN's JVM.

Now in weblogic for a domain the most important configuration file is config.xml which is the central configuration file for a domain.