The LowLevelSource maintains a list of what messages are in-flight but not yet acked. During graceful shutdown, it should nack everything in this list so that Pubsub can quickly re-send the messages to another pod. But because of a subtle bug, the pubsub Subscriber was getting shutdown before those messages got nacked.
The LowLevelSource maintains a list of what messages are in-flight but not yet acked. During graceful shutdown, it should nack everything in this list so that Pubsub can quickly re-send the messages to another pod. But because of a subtle bug, the pubsub Subscriber was getting shutdown before those messages got nacked.