Google ACE Planning and Configuring a Cloud Solution Practice Question

Answer analysis

Option-by-option breakdown

For each option: why learners choose it and why it is or isn't the right answer here.

• ✓

  Cloud Functions (2nd gen) with an event-driven trigger from Pub/Sub and retry on failure

  Why this is correct

  Cloud Functions (2nd gen) with an event-driven trigger from Pub/Sub and retry on failure is correct because 2nd gen functions are built on Eventarc and Cloud Run, which natively subscribe to Pub/Sub topics and invoke the function asynchronously when messages arrive. The 2nd gen runtime supports a maximum timeout of 60 minutes, comfortably covering the 10-minute processing window, and when combined with a retry policy, transient failures will cause the message to be redelivered without hitting a timeout ceiling.

• ✗

  Cloud Functions (1st gen) with an HTTP trigger and a Pub/Sub push subscription

  Why it's wrong here

  This option uses a 1st gen HTTP trigger with a Pub/Sub push subscription, which does allow messages to reach the function as HTTP POST requests, but the fundamental problem is the 1st gen HTTP function timeout is capped at 9 minutes. Because the processing takes 10 minutes, the function execution will be forcibly terminated regardless of the push subscription's own retry mechanisms; the push subscription only redelivers the message, it cannot extend the function's execution time, so every retry will also time out and fail.

• ✗

  Cloud Functions (2nd gen) with an HTTP trigger

  Why it's wrong here

  A 2nd gen HTTP trigger is not wired to Pub/Sub in an event-driven manner; HTTP functions are invoked by direct HTTP requests, not by Pub/Sub message delivery. To automatically process Pub/Sub messages, the function needs an Eventarc trigger that listens to the Pub/Sub topic and sends the event to the function's event-driven endpoint—an HTTP trigger would require you to manually create a push subscription or write custom polling logic, which is not the native, managed integration Cloud Functions provides for Pub/Sub.

• ✗

  Cloud Functions (1st gen) with a background function and retry on failure

  Why it's wrong here

  A 1st gen background function with retry enabled still carries the 1st gen maximum timeout of 9 minutes, which is less than the required 10-minute processing time. Retry does not reset or extend the execution deadline; it simply re-invokes the function after a failure, so each attempt will again time out at 9 minutes and continue to fail indefinitely. Background functions in 1st gen also use the same underlying infrastructure as App Engine, which enforces this strict timeout, making the option unsuitable regardless of the retry policy.

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