Node
A node is a logical grouping of managed servers.
A node usually corresponds to a logical or physical computer system with a distinct IP host address. Nodes cannot span multiple computers. Node names usually are identical to the host name for the computer.
Nodes in the network deployment topology can be managed or unmanaged. A managed node has a node agent process that manages its configuration and servers. Unmanaged nodes do not have a node agent.
A managed node has a node agent that manages all servers on a node...
- WAS servers
- JMS servers (V5 nodes)
- Web servers
- generic servers
The node agent represents the node in the management cell and keeps the configuration up to date.
An unmanaged node does not have a node agent to manage its servers. Unmanaged nodes in the ND environment can have server definitions such as Web servers, but not Application Server definitions. Unmanaged nodes in the ND environment cannot have a node agent added to it, and therefore cannot become a managed node.
In the stand-alone Application Server environment, nodes do not have node agents and are also considered unmanaged nodes.
The deployment manager cannot manage a stand-alone Application Server because it is not known to the cell. A stand-alone Application Server can be federated. When it is federated, a node agent is automatically created, and the node becomes a managed node in the cell.
A supported Web server can be on a managed node or an unmanaged node. You can define only one Web server to a stand-alone WAS node. This Web server is defined on an unmanaged node. You can define Web servers to the deployment manager. These Web servers can be defined on managed or unmanaged nodes.
WAS supports basic administrative functions for all supported Web servers. For example, the generation of a plug-in configuration can be performed for all Web servers. However, propagation of a plug-in configuration to remote Web servers is supported only for IBM HTTP Servers that are defined on an unmanaged node. If the Web server is defined on a managed node, propagation of the plug-in configuration is done for all the Web servers by using node synchronization. The Web server plug-in configuration file is created according to the Web server definition and is based on the list of applications that are deployed on the Web server. You can also map all supported Web servers as potential targets for the modules during application deployment.
WAS supports some additional console tasks for IBM HTTP Servers on managed and unmanaged nodes. For instance, you can start IBM HTTP Servers, stop them, terminate them, display their log files, and edit their configuration files.
You can add managed and unmanaged nodes to a ND cell in one of the following ways:
- Administrative console
- Command line (managed nodes only)
- Administrative script
- Java program
Each of these methods for adding a managed node to a ND cell includes the option of specifying a target node group for the managed node to join. If you do not specify a node group, or you do not have the option of specifying a node group, the default node group of DefaultNodeGroup is the target node group.
Whether you specify an explicit node group or accept the default, the node group membership rules must be satisfied. If the node that you are adding does not satisfy the node group membership rules for the target node group, the add node operation fails with an error message.
Related concepts
Node group
Related tasks
Manage nodes
Set up the administrative architecture
Communicate with Web servers
Install IBM HTTP Server
Manage node group members