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.