Sun GlassFish Enterprise Server 2.1 Administration Guide

Node Agent

A lightweight agent (e.g. hosting a JMX runtime only) is required on each node in the domain to facilitate remote lifecycle management of instances. Its primary purpose is to start, stop, and create server instances as instructed by the DAS. The Node Agent also acts as a watchdog and restarts failed processes. Like the DAS, the Node Agent should only be required for certain administrative operations and should not be expected to be highly available. However, the Node Agent is an “always on” component, and must be configured to be started by the native O/S node bootstrap (e.g. Solaris/Linux inetd, or as a Windows service). A Node Agent is not required for the DAS.