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On “Performance of NATS Jetstream”
Publishing in NATS JetStream is slightly different than publishing in Core NATS.
Yes, you can publish a Core NATS message to a subject that is recorded by a stream and that message will indeed be captured in the stream, but in the case of the Core NATS publication, the publishing application does not expect an acknowledgement back from the nats-server, while in the case of the JetStream publish call, there is an acknowledgement sent back to the client from the nats-server that indicates that the message was indeed successfully persisted and replicated (or not).
So when you do js.Publish() you are actually making a synchronous relatively high latency request-reply (especially if your replic…