Use full info about Weblogic

Use full info about Weblogic

WebLogic Server Instance

             

                A WebLogic Server instance is a Java Virtual Machine (JVM) process that runs the Java code. The instance is the actively working component, receiving client requests and sending them on to the appropriate components, and sending the processed requests back to the clients. Weblogic server instance is combination of admin server + manage server.

Administration Server

            A server is an instance of WebLogic Server that runs in its own JVM, and the Admin Server is a special instance of  WebLogic Server designed for managing the domain rather than running applications. There is a one-to-one relationship between domains and the Admin Server—an Admin Server belonging to Domain A can’t manage Domain B.

            You can deploy applications on the Admin Server, but unless you’re operating in a purely developmental environment, use the Admin Server strictly for performing management tasks, not for deploying any applications. Although you can deploy applications on the Admin Server in a development environment, it’s a best practice not to do so in a production environment

Managed Server

            Managed servers are the workhorses of WebLogic Server. Any additional servers you create after the creation of the default Admin Server are Managed Servers. The Managed Server contacts the Admin Server, only when you start it up, to get the configuration and deployment settings. For this reason, you should always start up the Admin Server before you start a Managed Server. Once a Managed Server starts running, it operates completely independent of the Admin Server.

WebLogic Server Cluster

            A WebLogic Server cluster is a group of WebLogic Server instances consisting of multiple Managed Servers that run simultaneously.

Machine

            A machine in the WebLogic Server context is the logical representation of the computer that hosts one or more WebLogic Server instances (servers).

Node Manager

            Node Managers help you remotely start, stop, suspend, and restart Managed Servers.

Services

Following are some of the main services used in a WebLogic environment:

■ JDBC (Java Database Connectivity) enables Java programs to handle database

connections established through connection pools.

■JMS (Java Messaging Service) is a standard API that enables applications to communicate

through enterprise messaging systems.

■JTA (Java Transaction API) specifies standard Java interfaces between transaction

managers and the parties in a distributed transaction system.

Development and Production Mode

            By default, WebLogic Server domains run in the development mode using the Sun Java Development Kit (JDK). In this mode, auto-deployment of applications is enabled and the Admin Server creates a boot.properties file automatically when you start it up. You can also use the demo certificates for Secure Sockets Layer (SSL) without any warnings from WebLogic Server. The development mode is provided to get developers up and running quickly without having to worry

about advanced deployment, configuration, or security issues.

In the production mode, WebLogic Server defaults to using JRockit as the default JDK. In addition, you can’t use the auto-deployment feature in production, and WebLogic Server issues warnings if you use the demo certificates for SSL. In the production mode, you’re also prompted for usernames and password when you start up the instances.

It’s easy to toggle between the development and production modes