You are troubleshooting a performance issue for an Azure Application Gateway.
You need to compare the total requests to the failed requests during the past six hours.
What should you use?
Azure Application Gateway is a web traffic load balancer that enables you to manage traffic to your web applications. Traditional load balancers operate at the transport layer (OSI layer 4 - TCP and UDP) and route traffic based on source IP address and port, to a destination IP address and port.
With Application Gateway, you can make routing decisions based on additional attributes of an HTTP request, such as URI path or host headers. For example, you can route traffic based on the incoming URL. So if /images is in the incoming URL, you can route traffic to a specific set of servers (known as a pool) configured for images. If /video is in the URL, that traffic is routed to another pool that's optimized for videos.
This type of routing is known as application layer (OSI layer 7) load balancing. Azure Application Gateway can do URL-based routing and more.
By using Azure Application Gateway, you can monitor resources in the following ways:
Back-end health: Application Gateway provides the capability to monitor the health of the servers in the back-end pools through the Azure portal and through PowerShell. You can also find the health of the back-end pools through the performance diagnostic logs.
Logs: Logs allow for performance, access, and other data to be saved or consumed from a resource for monitoring purposes.
Metrics: Application Gateway has several metrics which help you verify that your system is performing as expected.