1.2 Key Concepts

Figure 1–1 illustrates the key concepts of the Java DMK and shows how the components relate to each other.

In this example, the MBeans for two resources are registered with the agent's MBean server. An agent service such as monitoring is registered as another MBean. The agent contains a connector server for one of either the RMI or JMXMP connector protocols. The agent also contains a protocol adaptor, either for SNMP or HTML. An agent can have any number of communicator components, one for each of the protocols, and one for each of the ports through which it communicates.

Figure 1–1 Key Concepts of the Java DMK

The remote manager is a Java application running on a distant host. The manager contains the connector client for the chosen protocol and proxy MBeans representing the two resources. When the connector client establishes the connection with the agent's connector server, the other components of the application can issue management requests to the agent. For example, the connector client can call the proxy objects to invoke an operation on the first resource and configure the monitoring service to poll the second resource.

With the HTML adaptor, you can view the agent through a web browser, which provides a simple user interface. Each MBean is represented as a separate HTML page, from which you can interact with text fields to set attributes and click buttons to invoke operations. The HTML adaptor also provides an administration page for creating or removing MBeans from the MBean server.

Each of these concepts is further defined in Chapter 2, Architectural Components.