This is in continuation of my previous blog Understanding Architecture of WebLogic Server.

In this blog we will be mainly discussing:

  1. Terminology
  2. Components of a WebLogic Server Domain


Web Services

  • They are server-side services, for application-to-application communication.
  • They are accessible over the web using well-known protocols
  • They are described using XML
  • They interact using XML
  • They operates fully across platforms


Web server

  • It provided Web content
  • It communicates by HTTP, FTP, and so on.
  • It can be proxy request to other servers


Application Server

  • It provides services that support the execution and availability of deployed applications
  • It handles heavier processing task than a Web server does.


Proxy Server

  • It forwards the requests to other machines
  • It can be used as a level of indirection and security
  • It can be used to balance the load on a system
  • Web servers can act as proxy servers



  • It provides filtering, authorization, and authentication services
  • It helps keep hackers out
  • It maps ports requests
  • It can act as a proxy server
  • It can decrease back-end network activity.


Web Client

  • A Web Client interacts with WLS with HTTP, using Servlets and JSPs.
  • The types of Web clients include:
  1. Browser
  2. Web services



Client Application

  • A client application interacts with WLS through JRMP/T3, IIOP and COM.
  • The types of clients include these:
    1. Stand-alone Java application
    2. Browser application



Definition: Server

  • A Server is an instance of weblogic.Server executing in a JVM.
  • A Server:
    1. Runs on s designated WLS machine
    2. Has a dedicated amount of RAM
    3. Is multi-threaded


Definition: Machine

  • A machine is a computer that hosts Weblogic Servers(s)
  • A machine can host multiple Weblogic Server instances
  • A machine runs a supported operating system platform


Definition : Cluster

  • A cluster is a logical group of WLS servers.
  • Weblogic cluster provide automatic
    1. Fault tolerance
    2. High Availability
    3. Load-balancing
  • A cluster is transparent to client


Definition: Domain

  • Domain is logically related group of Weblogic Server resources that we manage as unit
  • A domain provides one point of administration
  • A Weblogic Server can logically separate:
    1. Development, test and production applications
    2. Organizational divisions


Why Use Domain

  • A domain is an administrative feature that:
    1. Is transparent to application
    2. Can be configured and administered, for technical or business reasons, even after applications are developed or in production
  • Weblogic Server domains can be used to separate:
    1. Development, test and production application
    2. Administration and operational responsibilities
    3. Organizational or business divisions


Definition: Administration Server

  • An administration server is central point of control for a domain
  • An admin server:
    1. Stores the configuration information and logs for a domain
    2. Runs the Weblogic admin console


Definition: Managed Server

  • A managed server is any server that is not the admin server
  • A managed server:
    1. Contacts the admin server for configuration information
    2. Runs business application in a production environment


A Web Application Server Configuration


An Application Server Configuration



A Big Picture



 Hope this blog helps you with better understanding of weblogic.



12+ Year IT professional SME with expertise in Middleware, Cloud Computing & DevOps Methodology.