Welcome to basic administrative architecture
The basic administrative architecture consists of software processes called servers, topological units referenced as nodes and cells, and the configuration repository used for storing configuration information. The appserver, node agent server, and deployment manager server interact to perform system administration.
This article discusses basic concepts in the administrative architecture to help you understand system administration in a WAS environment.
Servers perform the actual running of the code. Several types of servers exist depending on the configuration. Each server runs in its own JVM. The appserver is the primary run-time component in all WAS configurations. All WAS configurations can have one or more appservers. In some configurations, each appserver functions as a separate entity. No workload distribution or common administration among appservers exists. In other configurations, workload can be distributed between servers and administration can be done from a central point.
A node is a logical group of WAS-managed server processes that share a common configuration repository. A node is associated with a single WebSphere Application Server profile. A WAS node does not necessarily have a one-to-one association with a system. One computer can host arbitrarily many nodes, but a node cannot span multiple computer systems. A node can contain zero or more appservers.
The configuration repository holds copies of the individual component configuration documents that define the configuration of a WAS environment. All configuration information is stored in .xml files.
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. When a node becomes part of a cell (a federated node), a node agent server is installed on the node to work with the deployment manager server to manage the WAS environment on that node.
When a node is a standalone node, not part of a cell, the configuration repository is fully contained on the node. When a node is part of a cell, the configuration and application files for all nodes in the cell are centralized into a cell master configuration repository. This centralized repository is managed by the deployment manager server and synchronized to local copies that are held on each node. The local copy of the repository that is given to each node contains just the configuration information needed by that node, not the full configuration that is maintained by the deployment manager.
WAS types
Application Server A WAS provides the functions that are required to support and host user applications. An appserver runs on only one node, but one node can support many appservers. Node agent When a node is federated, a node agent is created and installed on that node. The node agent works with the deployment manager to perform administrative activities on the node. Deployment manager With the deployment manager, you can administer multiple appservers from one centralized manager. The deployment manager works with the node agent on each node to manage all the servers in a distributed topology.
The following diagram depicts the concepts that are discussed in this article.
The concepts that are discussed in this article form the basis of WAS administration. More detailed descriptions can be found in other sections.
Related tasks
Set up the administrative architecture