Understanding The Components of a Streaming Media Network – Part 2

Reporting & Monitoring Systems
Reporting and monitoring a CDN’s activity are two separate tasks with differing goals. A reporting system looks back historically at usage while a monitoring system deals with real-time statistics. The reporting system would be used post mortem to generate reports and invoices based upon viewer usage. Typical reporting queries are "How long, on average, did people watch the conference?" and "How many viewers were on the network between 2pm and 3pm?" The monitoring system is used by the network administrator to make sure all is well on the network.

A monitoring system is a snapshot of the state of the network at the current point in time. The monitoring system is like the dashboard on an automobile. It lists all the critical information about the network: total connected clients, total instantaneous egress bandwidth, live feeds being broadcast etc. This is useful for an administrator to gage the activity on the network and keep tabs on events. A monitoring system is tied in directly with the streaming servers and retrieves real-time information from the streaming servers themselves. Typically, server logs do not contain enough information or are not generated in a timely fashion to be used by a monitoring system. The streaming server needs to contain hooks, an interface into the guts of the server, for use by the monitoring system. Monitoring systems do not typically maintain historical information going back to the beginning of time. They may maintain historical data going back a few minutes to a few hours but do not log data day after day. Usually, historical data is typically dealt with by a reporting system.

The reporting system on a CDN logs data going back to first data delivered by the streaming servers. Data is kept in persistent memory, typically a database, where it can be queried to generate reports. The interface to the reporting system can vary from a standalone application, a web based interface or simply a hook into the database to be accessed via some 3rd party database tools such as Microsoft Access, Excel or Crystal Reports. The reporting system processes the log files from the streaming servers and stores them in the database. By digesting the logs, the reporting system can more efficiently generate reports based upon the desired queries.One important aspect of reporting is to keep the raw logs files to go back and revalidate the reports. When a log is processed by a reporting system it stores the data in a proprietary format in the database. If you ever switch to another reporting system you will need those logs to populate the database of your new reporting system. Additionally, companies that measure audience size, such as Arbitron, may require the raw log files for audience count verification.

Next Page: Streaming Servers >>