When Azure Application Gateways route traffic to your application, you can generally expect a steady stream of requests to your application. Blue Matador watches the Throughput metric for the number of bytes going in and out of your application gateway and creates events when this metric is anomalous. A change in the number of bytes processed can be caused by two things:
- Request rate has increased/decreased
- Request or response sizes have increased/decreased
Neither of these two situations are guaranteed problems. However, it can be useful to know when your application gateway spikes or drops in traffic, especially if it happens in a pattern you were previously unaware of. Knowing about anomalous traffic can also be useful for correlation with other infrastructure issues you’re experiencing.
If you determine that the difference in bytes processed is significant, enable and check access logs for your application gateway. This can help you find which endpoints are being called with a different frequency or that have unexpected response sizes.
