Application Gateway Features

Azure Application Gateway is a web traffic load balancer that enables you to manage traffic to your web applications. It offers advanced routing capabilities, security features, and performance optimizations. This article delves into the core features that make Application Gateway a robust solution for modern web application deployments.

Key Features of Azure Application Gateway

  • Load Balancing

    Application Gateway provides Layer 7 (HTTP/HTTPS) load balancing, distributing incoming traffic across multiple backend instances of your web applications. It supports both round-robin and session affinity (sticky sessions) for flexible traffic distribution.

  • SSL/TLS Termination

    Offload the decryption of SSL/TLS traffic from your web servers to Application Gateway. This simplifies server management and improves performance. Application Gateway supports end-to-end SSL encryption, ensuring secure communication from the client to the backend server.

    Learn more about SSL/TLS termination and end-to-end SSL encryption.

  • Web Application Firewall (WAF)

    Application Gateway's WAF provides centralized protection for your web applications against common web exploits and vulnerabilities, such as SQL injection, cross-site scripting (XSS) attacks, and more. It offers both managed and custom rule sets to suit your security needs.

    Explore Application Gateway WAF configurations.

  • Path-based Request Routing

    Direct traffic to different backend pools based on the request URL path. For example, requests to /images/* can be routed to one set of servers, while requests to /api/* can be routed to another.

    See how to configure path-based routing.

  • Host-based Request Routing (Multi-site Hosting)

    Host multiple web applications on the same Application Gateway instance by directing traffic to different backend pools based on the host header of the incoming request. This is ideal for scenarios where you host multiple domain names or subdomains.

    Details on multi-site hosting.

  • Redirection

    Configure HTTP to HTTPS redirection to enforce secure connections. You can also redirect traffic to a different URL based on request attributes.

  • URL Rewrite

    Modify request URLs before they are forwarded to the backend servers. This can be useful for simplifying URLs or for backend applications that expect specific URL formats.

  • Session Affinity (Cookie-based)

    Ensure that requests from a specific client are consistently directed to the same backend server throughout their session. This is crucial for applications that maintain session state on the server.

  • Health Probes

    Application Gateway continuously monitors the health of your backend instances. If an instance becomes unhealthy, traffic is automatically rerouted to healthy instances, ensuring application availability.

  • Autoscaling and Zone Redundancy

    Configure Application Gateway to automatically scale its capacity based on traffic load. Zone redundancy provides high availability by distributing the gateway across multiple Azure availability zones.

Advanced Routing and Security

Application Gateway's advanced routing rules and integrated WAF empower developers and administrators to build resilient, secure, and scalable web applications. By centralizing these functionalities, it reduces the complexity of managing individual web server configurations.

For detailed configuration guidance and best practices, refer to the official Azure Application Gateway documentation.