Google ACE Practice Question: Ensuring Successful Operation of a Cloud Solution

Answer analysis

Option-by-option breakdown

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

• ✗

  Increase the ack deadline

  Why it's wrong here

  Increasing the ack deadline gives subscribers more time to acknowledge a message before it is redelivered. While this can reduce duplicate processing, it does not reduce the end-to-end latency caused by a growing backlog; in fact, it can make latency worse by delaying redelivery of messages that a stuck subscriber failed to process. The root cause of intermittent high latency is usually insufficient processing capacity, not a too-short acknowledgement window.

• ✗

  Increase the maximum message size

  Why it's wrong here

  Increasing the maximum message size allows larger payloads to be published, but it does nothing to speed up delivery or processing of existing messages. The latency spike is unrelated to the size of individual messages unless the payloads are so large that they saturate the network or memory—an uncommon scenario. This setting has no effect on subscriber throughput or backlog clearance, so it will not resolve intermittent high latency.

• ✗

  Increase the message retention duration

  Why it's wrong here

  Extending message retention duration simply keeps undelivered messages in the topic or subscription for a longer period before they expire. It does not accelerate delivery or reduce the time a message spends waiting in the backlog. Since the problem is latency—not data loss or retention policy—increasing retention only delays when messages are discarded, without improving subscriber performance or reducing queue depth.

• ✓

  Increase the number of subscribers

  Why this is correct

  Increasing the number of subscribers (i.e., scaling out the subscriber fleet) directly raises the aggregate processing throughput of the subscription. Because the intermittent high latency is likely due to a backlog of messages accumulating faster than the current subscribers can drain, adding more subscribers allows messages to be pulled and processed in parallel, reducing the queue depth and lowering end-to-end latency. This is the correct scaling action for a latency problem caused by insufficient compute, assuming the subscribers are stateless and can process messages independently.

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