2. Sensing (Monitoring) the Service State : 2.1 Monitoring Approaches : 2.1.2 Stream Monitoring
   
2.1.2 Stream Monitoring
Stream monitoring is where we passively monitor the service by “listening” to streams of data between the application and the end user or components of the application. This is typically done at the network packet layer and introduces little to no overhead on the service itself. Stream monitoring provides benefits over polled monitoring. Every session is observed as it occurs and, therefore, events should not go unnoticed. However, stream monitoring is typically far more complex and costly than polled monitoring.
Though it provides the benefits of real-time visibility, stream monitoring has the following issues:
*Increased complexity and cost.
*It is application specific and not supported by all applications.