Managing node agents

Node agents are administrative agents that represent a node to your system and manage the servers on that node. Node agents monitor application servers on a host system and route administrative requests to servers.

Before you begin

Before you can manage a node agent, you must install the WebSphere® Application Server Network Deployment product.

If you plan to change the system clock, stop all the application servers, the node agent servers, the deployment manager server, the administrative agent server, and the job manager server first. After you stop the servers, change the system clock, and then restart the servers.

For z/OS, also stop and then restart the location service daemon.

If you change the system clock on one system, you must ensure the clocks on all systems that communicate with each other and have WebSphere Application Server installed are synchronized. Otherwise, you might experience errors, such as security tokens no longer being valid.

About this task

A node agent is a server that is created automatically when a node is added to a cell. A node agent runs on every host computer system that participates in the WebSphere Application Server Network Deployment product. You can view information about a node agent, stop and start the processing of a node agent, stop and restart application servers on the node that is managed by the node agent, and so on.

A node agent is purely an administrative agent and is not involved in application serving functions. A node agent also hosts other important administrative functions, such as file transfer services, configuration synchronization, and performance monitoring.

You can manage nodes through the wsadmin scripting tool, through the Java™ application programming interfaces (APIs), or through the administrative console. Perform the following tasks to manage nodes on an application server through the administrative console.

• View information about a node agent. Click System administration > Node agents in the console navigation tree. To view additional information about a particular node agent or to further configure a node agent, click the node agent name under Name.
• Stop and then restart all of the application servers on the node that is managed by the node agent. On the Node agents page, select the check box of the node agent that manages the node with servers that you want to restart, and click Restart all Servers on Node.

  Clicking Restart all Servers on Node also stops and then restarts the node agent. Servers that were stopped when you clicked Restart all Servers on Node remain stopped.

  The node agent for the node must be processing to restart application servers on the node.

• Stop the processing of a node agent. On the Node agents page, select the check box of the node agent that you want to stop processing; click Stop.

Results

Depending on the steps that you completed, you have viewed information about a node agent, stopped and started the processing of a node agent, and stopped and restarted application servers on the node that is managed by the node agent.

What to do next

You can administer other aspects of the WebSphere Application Server Network Deployment environment, such as the deployment manager, nodes, and cells.