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. 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.
Procedure
- 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.
IP
verions: Both Internet Protocol Version 4 (IPv4) and Internet
Protocol Version 6 (IPv6) are now supported by WebSphere Application Server, but there are restrictions that apply to using both IPv4 and
IPv6 in the same cell. Note that when a node is added to a cell, the
format in which the name is specified is based on the version of IP
the node will be using.
- Stop and then
restart the processing of a node agent. On the Node Agents page,
select the check box beside the node agent that you want to restart;
then click Restart. It is important to keep a node agent running
because a node agent must be running for application servers on the
node managed by the node agent to run.
- 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 beside 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.
Tip:
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 beside 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.