Exam Professional Data Engineer topic 1 question 228 discussion

DE Another way to replay messages that have been acknowledged is to seek to a timestamp. To seek to a timestamp, you must first configure the subscription to retain acknowledged messages using retain-acked-messages. If retain-acked-messages is set, Pub/Sub retains acknowledged messages for 7 days. You only need to do this step if you intend to seek to a timestamp, not to a snapshot. https://cloud.google.com/pubsub/docs/replay-message

B and E, already tested at cloud console.

DE. The questions says "Delivered Messages", so this are a acknowledged messages, this can only do the D. retain-acked-messages flag. Snapshot only save the unacknowledged messages, so, you miss the acknowledged to make a reprocess. And Letter E is mandatory to comeback in time.

The only way to ensure that the updated pipeline reprocesses the previous two days of delivered Pub/Sub messages (current) is to use B&E.... for future D&E can work.

Since E is seek to a timestamp only one to replay, I think D is correct answer and not B

D and E Please seem to not understand that the retain_acked_messages parameter needs to be enabled for any snapshot or seeking functionality to work.

After reading https://cloud.google.com/pubsub/docs/replay-overview#snapshot_overview carefully, B and E are correct.

First, read this document: https://cloud.google.com/pubsub/docs/replay-overview. Key Points: Seek to a Snapshot: Reprocesses only unacknowledged messages. Seek to a Timestamp: Reprocesses all messages (acknowledged and unacknowledged) after that time. Since the question asks for delivering all messages, option E is correct, as it includes both acknowledged and unacknowledged messages. Regarding Option D: Configuring a subscription with the retain_acked_messages property allows replaying previously acknowledged messages retained for up to 31 days. This satisfies the requirement to deliver all messages and retains them longer than the mentioned 2 days.

B&D - based on Vertex AI feedback

BE B. Use Pub/Sub Snapshot capture two days before the deployment. Pub/Sub Snapshot: Creating a snapshot captures the state of the subscription at a specific point in time. You can then seek to this snapshot to replay messages from that point onwards. By capturing a snapshot two days before the deployment, you can ensure that your pipeline reprocesses messages from the past two days. E. Use Pub/Sub Seek with a timestamp. Pub/Sub Seek: This feature allows you to reset the subscription to a specific timestamp. Messages published to the topic after this timestamp are re-delivered. By seeking to the timestamp from two days ago, you can instruct Pub/Sub to start re-delivering messages from that point in time

D. Use the Pub/Sub subscription retain-acked-messages flag. E. Use Pub/Sub Seek with a timestamp.

E for sure, you need to seek from a timestamp. To accomplish to that you need to "Set the retain-acked-messages flag to true for the subscription." From google documentation: "Note: To seek to a previous time point, your subscription must be configured to retain acknowledged messages. You can change this setting by clicking Edit on the subscription details page, and checking the box for Retain acknowledged messages." https://cloud.google.com/pubsub/docs/replay-message

D and E, https://cloud.google.com/pubsub/docs/replay-message

B and E: The seek feature extends subscriber capabilities by allowing you to alter the acknowledgement state of messages in bulk. For example, you can replay previously acknowledged messages or purge messages in bulk. In addition, you can copy the acknowledgement state of one subscription to another by using seek in combination with a snapshot. Source: https://cloud.google.com/pubsub/docs/replay-overview

BE https://cloud.google.com/pubsub/docs/replay-overview

Option D and E

DE Set the retain-acked-messages flag to true for the subscription. This instructs Pub/Sub to store acknowledged messages for a specified retention period. E Use Pub/Sub Seek with a timestamp. After deploying the updated pipeline, use the Seek feature to replay messages. Specify a timestamp that's two days before the current time. This rewinds the subscription's message cursor, making it redeliver messages from that point onward.