What is Azure Application Gateway?

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.

Application Gateway can make routing decisions based on additional attributes of an HTTP request, for example 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.

Note

Azure provides a suite of fully managed load-balancing solutions for your scenarios. If you need high-performance, low-latency, Layer-4 load balancing, see What is Azure Load Balancer? If you're looking for global DNS load balancing, see What is Traffic Manager? Your end-to-end scenarios may benefit from combining these solutions.

For an Azure load-balancing options comparison, see Overview of load-balancing options in Azure.

Features

To learn about Application Gateway features, see Azure Application Gateway features.