About real-time monitoring and control with RTMON

Overview of RTMON

The Real-Time Monitoring protocol (RTMON) is a NetCache proprietary XML-based protocol that is used for monitoring user streaming activity in real time. To use RTMON, an application server developer must program the interface on the server to the NetCache API for RTMON. Additionally, the appliance must be configured for RTMON.

Real-time monitoring is useful when you need your application servers to receive data while the activity occurs, instead of a reporting program extracting data from stored log files at a later time.

Real-Time Monitoring protocol (RTMON)

RTMON sends user streaming event data to specified application servers in real time. Data is sent using HTTP POST, at intervals that you specify. RTMON closes the connection at the end of each posting interval.

As the previous illustration shows, RTMON on the appliance listens for user streaming events from clients and sends that data to application servers. RTMON provides only monitoring. RTMON does not support application servers working with the appliance to exert any control over user streaming activity.

How an application server uses the monitored data depends on the type of server. For example:

An application server might store the data in a database for use for future billing, as shown in the previous illustration.
An application server in an ISP that wants to control the amount of time that a user is dialed in and streaming could send data that NetCache sends it to a database server that contains information about the amount of time users have been viewing. The database server could communicate with terminal servers to which users are logged in to close connections of users who have been dialed in and streaming too long. In this case, the application server does not interact with the appliance to control user activity. Instead, the server users the data from the appliance to interact with other devices that provide controls.

Feature summary: RTMON

The following table summarizes various aspects of how RTMON works.

Feature aspect	RTMON
Data sent between the appliance and application server	Status information Real-time monitoring of the following user streaming events: Connect Play Pause Set-bitrate Disconnect Dropped events Detailed data is available about each of these events. See Chapter 3, RTMON API, for details about events the appliance provides.
Application server control over streams	None. Only monitoring functions are available.
How the protocol communicates with the application server	Push RTMON sends messages about specified user activity to application servers by using HTTP POST. Connections are reestablished at the start of each (configurable) posting interval. TCP socket is also supported. See What occurs during failover for more information.
Implication of the communication model on technology that can be used by developers	Application server developers can implement Web server CGI scripts or Apache plug-in applications.
Simple Access Object Protocol (SOAP)	Not supported.
Configuration on the NetCache appliance	Configuration on the appliance determines which events and data are posted.
Schema (how the XML data is presented)	Data is sent through XML attributes. Example: <User Event-"play"CID=1 .../>