Question

A streaming Dataflow pipeline reads from a Pub/Sub subscription and writes aggregated metrics to BigQuery. After a production deployment, the team discovers that a transformation bug produced incorrect results for the last 6 hours. The subscription retains acknowledged messages, and message retention is set to 7 days. After deploying the corrected pipeline code, the team wants to reprocess the last 6 hours of messages without asking upstream publishers to resend anything. What is the most appropriate approach?

Accepted Answer

Use the Pub/Sub Seek operation to reset the subscription to a timestamp 6 hours in the past, then let the corrected pipeline consume the replayed messages.

Answer

Delete and recreate the subscription so the corrected pipeline starts from the earliest available message in the topic.

Answer

Create a snapshot of the topic and attach it to a new subscription to redeliver all messages ever published.

Answer

Increase the subscription's acknowledgment deadline so Pub/Sub automatically redelivers the previously processed messages.