1.1.3.3 Access Your Agents Remotely

Finally, the Java DMK enables you to access agents and their resources easily from a remote application. All components for handling the communication are provided, both in the agent and for the client application. The same API that is exposed by the MBean server in the agent is also available remotely to the manager. This symmetry effectively makes the communication layer transparent.

Management applications perform requests by getting or setting attributes or invoking operations on an MBean identified by its symbolic name. Proxy objects provide a further level of abstraction by representing an MBean remotely and handling all communication. The manager can be designed and developed as if all resources were local. The communication components also handle notification forwarding, so that remote managers can register to receive notifications from broadcasting MBeans.

Management applications developed in the Java programming language use connectors to make the communication layer transparent. Connectors for the RMI, RMI/IIOP and JMXMP protocols are provided, as defined by the JMX Remote API, all with the same API for interchangeability. The legacy RMI and HTTP-based connectors from previous versions of Java DMK are retained for reasons of backwards compatibility, but are deprecated in version 5.1. Wherever possible, you should migrate your remote agents to the standard JMX Remote API connectors.

Adaptors provide a view of an agent through other protocols for management applications which are not based on Java technology. For example, the HTML adaptor represents MBeans as web pages that can be viewed in any web browser. The SNMP adaptor can expose special MBeans that represent an SNMP MIB and respond to requests in the SNMP protocols. It is possible to use the SNMP adaptor without registering the MIB in the MBean server.

All connectors and adaptors are implemented as MBeans. Management applications can therefore create, configure and remove communication resources dynamically, according to network conditions or available protocols. Each protocol can have its own built-in security mechanisms, for example SSL, SASL, or SNMPv3 security. Security aspects linked to each protocol are therefore handled at the connector or adaptor layer, making them transparent to the MBean developer.

The flexibility of communicator MBeans and the availability of connectors for multiple protocols make it possible to deploy management solutions in heterogeneous network environments. The adaptors create a bridge between agents that are based on the JMX architecture and existing management systems. You can also create your own connectors and adaptors to accommodate proprietary protocols and future management needs.