Quality of Service Example

The following example shows how the quality of service information is collected and computed:

The server has metric interval of 30 seconds.

The server starts up at a time of 0 seconds.

At time 1 second, an HTTP connection generates 5000 bytes of traffic to/from the server.

No more connections are made after that. At 30 seconds, the total traffic for the last 30 seconds is 5000 bytes.

At 32 seconds, the traffic sample from 1 second is discarded, since it is older than the 30 seconds of the metric interval. The total traffic for the last 30 seconds is now 0.

The recompute interval works similarly. The server’s recompute interval is 100ms.

Continuing with the example, the bandwidth gets recomputed periodically every 100 milliseconds. The calculation is based on the amount of traffic as well as the metric interval.

At time 0 seconds, the bandwidth is calculated for the first time. The total traffic is zero, divided by the metric interval of 30 seconds, gives a bandwidth of zero.

At 1 second, the bandwidth is calculated for the 10th time (1000 milliseconds/ 100 milliseconds). The total traffic is 5000 bytes, which is divided by 30 seconds. The bandwidth is 5000/30 = 166 bytes per second.

At 30 seconds, the bandwidth is calculated for the 300th time. The total traffic is 5000 bytes, which is divided by 30 seconds. The bandwidth is 5000/30 = 166 bytes per second.

At 32 seconds, the bandwidth is computed again for the 320th time. The traffic is now 0 (since the one connection that generated traffic is too old to be counted), divided by 30, gives a bandwidth of 0 bytes/second.