What is the primary benefit of deploying an Azure Application Gateway for an app with cookie-based affinity requirements?

Deploying an Azure Application Gateway offers the primary benefit of ensuring consistent session management, particularly in scenarios that require cookie-based affinity. This mechanism, often referred to as session persistence, allows the Application Gateway to direct requests from a specific client to the same backend server for the duration of the session.

When a user initiates a session, the Application Gateway can create a session cookie that associates the user’s requests with a particular backend instance. This is critical for applications that maintain state information (such as user authentication or shopping carts) throughout the user’s session. Without this capability, a user's requests could be distributed across different servers, leading to inconsistent experiences where session data may not be shared across different instances, thus breaking the desired functionality of the application.

The other aspects related to read/write speeds, server costs, and scale sets, while valuable in certain contexts, do not directly address the requirement for cookie-based affinity. Read/write speeds may be influenced by various factors including database optimization and caching strategies, but they are not specifically tied to session management. Similarly, while Application Gateways can work with virtual machine scale sets to improve scalability and performance, that feature does not specifically cater to the needs of session persistence. Lastly, while leveraging an Application Gateway may optimize resource