[alexatkeplar]

Not sure why you are comparing Google Cloud Pub/Sub to Kinesis - the former is a MQ system, not a distributed commit log.

When creating a Kinesis consumer, I can specify whether I want to start reading a stream from a) TRIM_HORIZON (which is the earliest events in the stream which haven't yet been expired aka "trimmed"), b) LATEST which is the Cloud Pub/Sub capability, c) AT_SEQUENCE_NUMBER {x} which means from the event in the stream with the given offset ID, d) AFTER_SEQUENCE_NUMBER {x} which is the event immediately after c), e) AT_TIMESTAMP to read records from an arbitrary point in time.

A Kinesis stream (like a Kafka topic) is a very special form of database - it exists independently of any consumers. By contrast, with Google Cloud Pub/Sub [1]:

> When you create a subscription, the system establishes a sync point. That is, your subscriber is guaranteed to receive any message published after this point.

[1] https://cloud.google.com/pubsub/subscriber

So the stream is not a first class entity in Cloud Pub/Sub - it's just a consumer-tied message queue.

[nivertech]

Is there something like Kinesis' AT_TIMESTAMP in Kafka?

I think the only way in to replay events in Google Cloud Pub/Sub is to create multiple subscriptions in advance, right after topic creation. But then I think you need to pay for the storage and event traversal requests.