In enterprise java application world, Websphere is the most used application server. IBM has created websphere as its product for long time now. Other alternatives have been JBoss and Tomcat. (Though tomcat is not a full fledged application server and there is a debate about it.)
In this post, we will discuss basic concepts of IBM Websphere Application Server. If you have any questions, please post them in comment and I will try to answer them to the best of my abilities.
Application Server – Primary component of IBM websphere is application server. The server runs the actual code of your application. Each server runs its own Java Virtual Machine (JVM). All configurations can have one or more application servers. An application server can run on only one node, but one node can support many application servers.
Node – It is a logical group of application server-managed server processes that share common configuration repositories. A single node is related to a single profile. One machine can have more than one nodes. A node can contain zero or more application servers. The configuration information which Node is useful for, is stored in *.xml file.
Cell – A cell is a grouping of nodes into a single administrative domain. A cell can consist of multiple nodes, all administered from a deployment manager server.
Node Agent – A node agent is created on Node when a node is federated. The node agent works with the deployment manager for administrative activities.
Deployment Manager – With the deployment manager, you can administer multiple nodes from one centralized manager. This deployment manager works with node agent on each node. Application server nodes must be federated with the deployment manager before they can be managed by the deployment manager.