I actually didn’t realize that the expected last sequence could be combined with nats-rollup. In the example above (as I understand it) if we added that to the snapshot, NATS would throw out the snapshot, so the log would still be correct, but the work of snapshotting it and sending it over the wire would be lost. If messages were frequent enough, and/or snapshots took a while to compute/transfer, you might never have a roll-up succeed.
Our approach is that a roll-up will always succeed, we just preserve any messages in the stream with a sequence number greater than the one provided.
(I’m enjoying it too, and am a user of NATS so I’m happy to learn things I didn’t know about it :)
I actually didn’t realize that the expected last sequence could be combined with nats-rollup. In the example above (as I understand it) if we added that to the snapshot, NATS would throw out the snapshot, so the log would still be correct, but the work of snapshotting it and sending it over the wire would be lost. If messages were frequent enough, and/or snapshots took a while to compute/transfer, you might never have a roll-up succeed.
Our approach is that a roll-up will always succeed, we just preserve any messages in the stream with a sequence number greater than the one provided.
(I’m enjoying it too, and am a user of NATS so I’m happy to learn things I didn’t know about it :)