Websphere Basics

What is WAS

Provides the infrastructure for running applications that run your business.

Common environment and programming model for your applications.

Platform for developing and Deploying web services and SOA based apps

Secure, Scalable, reliable transaction engine for ERP

IBM WebSphere is architected to enable you to build business-critical applications for the Web WebSphere includes a wide range of products that help you develop and serve Web applications.

They are designed to make it easier for clients to build, deploy, and manage dynamic Web sites more   productively

WAS implements J2EE specification

WebSphere Application Server provides the environment to run your Web-enabled e-business applications. An application server functions as Web middleware or a middle tier in a three-tier e-business environment. The first tier is the HTTP server that handles requests from the browser client. The third tier is the business database (for example, DB2 UDB for iSeries) and the business logic (for example, traditional business applications, such as order processing). The middle tier is WebSphere Application Server, which provides a framework for a consistent and architected link between the HTTP requests and the business data and logic.

With the Base and Express packages, you are limited to single application server environments. The Network Deployment package allows you to extend this environment to include multiple application servers that are administered from a single point of control and can be clustered to provide scalability and high availability environments.

Below, you will find definitions for each of the terms shown in the graphic above.

Cell

A cell is a grouping of nodes into a single administrative domain. ... In a Network

Deployment environment, a cell can consist of multiple nodes (and node groups), which are

all administered from a single point, the deployment manager

Cluster

A cluster is defined as "a group of application servers that collaborate for the purposes of

workload balancing and failover" in the WebSphere Application Server Glossary.

In other words:

... A cluster is a logical collection of application server processes that provides workload

balancing and high availability.

Deployment Manager

A Deployment Manager is "a server that manages or administrate  the operations for a logical group or cell of otherservers,"

... the central administration point of a cell that consists of multiple nodes and node groups

in a distributed server configuration. ... The deployment manager uses the node agent to

manage the application servers within one node. A deployment manager provides

management capability for multiple federated nodes and can manage nodes that span

multiple systems and platforms.

 A node can only be managed by a single deployment

manager and must be federated to the cell of that deployment manager. The configuration

and application files for all nodes in the cell are centralized into a master configuration

repository. This centralized repository is managed by the deployment manager and

synchronized with local copies that are held on each of the nodes.

Node

Node is "a logical grouping of managed servers."

In particular:

A node is an administrative grouping of application servers

  With Network Deployment, you can configure a distributed server environment consisting of multiple

nodes, which are managed from one central administration server.

Node Agent

A Node agent's purpose is to pass information between the deployment

manager and the application server

In addition:

In distributed server configurations, each node has a node agent that works with the

deployment manager to manage administration processes... A node agent is created

automatically when you add (federate) a stand-alone node to a cell. It is not included in the

Base and Express® configurations.

.

Application Server

application server is " it provides the runtime environment for an e-business application program."

More specifically:

The application server is the primary runtime component in all configurations and is where

an application actually executes.

All WebSphere Application Server configurations can haveone or more application servers.

.With Network Deployment, you can build a distributedserver environment consisting of multiple application servers maintained from a centraladministration point. In a distributed server environment, you can cluster application

servers for workload distribution.

Profile

A profile is "Runtime configurations for the websphere application servers."

Types of profiles:

Cell

– This environment creates two profiles:

- A management profile with a deployment manager

- An application server profile added (federated) to the management profile

 Application server

– An application server profile runs your enterprise applications and makes them available to

the internet or to an intranet. It contains a stand-alone application server.

 Custom

– A custom profile contains an empty node with no servers. However, a server can be added

after the profile is created.

In7.0 additionally

Management

– A management profile provides components for managing multiple application server

environments. Possible profiles are as follows:

- Deployment manager

- Administrative agent

- Job manager