Professional Cloud Developer Exam - Question 94

Question

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?

Examice · Accepted Answer

Create one Pub/Sub topic. Create one pull subscription to allow the audit services to share the messages. This setup ensures that messages are distributed among multiple audit service instances efficiently and allows the system to scale horizontally. Each audit service can pull messages from the same subscription, which helps to handle a large volume of messages without creating a bottleneck. This approach simplifies the management of topics and subscriptions while providing the required scalability.

gfr892 · Answer

https://cloud.google.com/pubsub/docs/subscriber
"Multiple subscribers can make pull calls to the same "shared" subscription. Each subscriber will receive a subset of the messages."
Response is A.
With C and D you can't scale efficiently, because you have to create a topic for each new instance of the authentication service.

telp · Answer

A is correct. This is the most flexible way to scale, allowing the authentication and audit services to be sized independently according to load.
B is incorrect. This will cause messages to be duplicated, one copy per subscription.
C is incorrect. This will allow the system to scale, but push subscriptions are less suited to handle large volumes of messages.
D is incorrect. This will allow the system to scale, however each audit service will listen to all subscriptions.
E. is incorrect. This will allow the system to scale, however it will require each audit service to listen to all subscriptions. Also push subscriptions are less suited to handle large volumes of messages.

ParagSanyashiv · Answer

Agree with D

scaenruy · Answer

I vote C

tomato123 · Answer

A is correct I think

Blueocean · Answer

While this can be between C and D , I would go with Option D considering the large volume mentioned in question

zellck · Answer

A is the answer.

omermahgoub · Answer

Answer is E, in which there is one topic per authentication service and one push subscription per topic, with the endpoint pointing to one audit service, is a better option because it allows the audit services to scale horizontally to handle a large volume of messages, and it allows the messages to be processed in parallel. Each authentication service will send messages directly to its own topic, which will be handled by a specific audit service. This will ensure that the system can scale horizontally to handle a large volume of messages, and it will also allow the audit services to process the messages in parallel.

closer89 · Answer

i go for A + custom pubsub metric on autoscale

Yochen · Answer

In my opinion, Option C would be the most efficient way to handle the scenario. Here's why:

Single Topic: Having one Pub/Sub topic keeps things simpler and allows all authentication service instances to publish to the same topic.

Push Subscription with Load Balancer: This allows incoming messages to be distributed among all available audit service instances. The load balancer would handle distributing the load, making it easier for the audit service to scale out as needed.

Option C ensures both scalability and efficient handling of a large volume of messages.

Rajan · Answer

I would go with A.

braska · Answer

Option E is a more scalable and efficient solution for handling a large volume of messages and scaling efficiently.

Aeglas · Answer

Most simple and efficient one is A

thewalker · Answer

The best approach here is C. Create one Pub/Sub topic. Create one push subscription with the endpoint pointing to a load balancer in front of the audit services.

Here's why:

Scalability: A single Pub/Sub topic allows you to centralize all audit events. This makes it easy to scale the authentication services by adding more instances without needing to change the Pub/Sub configuration.
Load Balancing: Using a push subscription with a load balancer in front of the audit services ensures that the incoming messages are distributed evenly across the available audit service instances. This prevents any single instance from becoming overloaded.
Efficiency: Push subscriptions are more efficient than pull subscriptions for high-volume scenarios. This is because the Pub/Sub service actively pushes messages to the subscribers, reducing the need for the audit services to constantly poll for new messages.

Professional Cloud Developer Exam - Question 94

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