Google Cloud Professional Cloud Developer — Question 90

You need to redesign the ingestion of audit events from your authentication service to allow it to handle a large increase in traffic. Currently, the audit service and the authentication system run in the same Compute Engine virtual machine. You plan to use the following Google Cloud tools in the new architecture:
✑ Multiple Compute Engine machines, each running an instance of the authentication service
✑ Multiple Compute Engine machines, each running an instance of the audit service
✑ Pub/Sub to send the events from the authentication services.
How should you set up the topics and subscriptions to ensure that the system can handle a large volume of messages and can scale efficiently?

Answer options

• A. Create one Pub/Sub topic. Create one pull subscription to allow the audit services to share the messages.
• B. Create one Pub/Sub topic. Create one pull subscription per audit service instance to allow the services to share the messages.
• C. Create one Pub/Sub topic. Create one push subscription with the endpoint pointing to a load balancer in front of the audit services.
• D. Create one Pub/Sub topic per authentication service. Create one pull subscription per topic to be used by one audit service.
• E. Create one Pub/Sub topic per authentication service. Create one push subscription per topic, with the endpoint pointing to one audit service.

Correct answer: A

Explanation

Option A is correct because having one Pub/Sub topic with a single pull subscription allows multiple audit services to share the load efficiently, which is essential for handling a high volume of messages. The other options either complicate the architecture by creating multiple subscriptions or do not effectively utilize shared resources, which could lead to inefficiencies and scaling challenges.