Distributing Traffic Across Multiple Compute Engine Instances: Choosing Session Affinity

Choose the Right Session Affinity for Distributing Traffic Across Multiple Compute Engine Instances

Question

You have deployed a new internal application that provides HTTP and TFTP services to on-premises hosts.

You want to be able to distribute traffic across multiple Compute Engine instances, but need to ensure that clients are sticky to a particular instance across both services.

Which session affinity should you choose?

Answers

Explanations

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A. B. C. D.

B.

To distribute traffic across multiple Compute Engine instances and maintain session affinity for clients, a session affinity or sticky session mechanism is used. This mechanism ensures that once a client establishes a session with a particular instance, all subsequent requests from that client will be directed to the same instance.

The session affinity options given in the question are:

A. None: This option does not maintain any session affinity. Each new request from the client may be directed to a different Compute Engine instance, which may cause issues if the application requires session persistence.

B. Client IP: This option maintains session affinity based on the client's IP address. Each client is directed to a specific Compute Engine instance based on their IP address, ensuring that all subsequent requests from that client are sent to the same instance.

C. Client IP and protocol: This option maintains session affinity based on the client's IP address and the protocol used for the request (HTTP or TFTP). Each client is directed to a specific Compute Engine instance based on their IP address and the protocol used, ensuring that all subsequent requests from that client using the same protocol are sent to the same instance.

D. Client IP, port, and protocol: This option maintains session affinity based on the client's IP address, the source port used by the client, and the protocol used for the request. Each client is directed to a specific Compute Engine instance based on their IP address, source port, and the protocol used, ensuring that all subsequent requests from that client using the same port and protocol are sent to the same instance.

In this scenario, since the application provides both HTTP and TFTP services, option D (Client IP, port, and protocol) would be the most appropriate choice for session affinity. This ensures that clients are sticky to a particular instance across both services and that all subsequent requests from that client using the same port and protocol are sent to the same instance.