[subjects overlap with an existing stream] & [Consumer configuration not found for stream] errors in a loop

[vsTianhao]

If I create a NATS stream using nats stream add, starting the service results in the error io.nats.client.JetStreamApiException: subjects overlap with an existing stream [10065]. If I delete and clear the NATS data, starting the service results in the error Consumer configuration not found for stream: xx. When I try to create the NATS stream again, I get the same error again: subjects overlap with an existing stream. This happens repeatedly, even after three or four attempts.

Do I need to create the stream manually? Why do I need to create it manually when there's so much configuration involved?

[Saphri]

The NATS error "subjects overlap with an existing stream [10065]" occurs because JetStream enforces a strict "one message, one owner" rule. In NATS JetStream, no two streams are allowed to "listen" to or claim the same subject.

Its a typical beginner mistake with NATS... I did the same when I started as I came from a IBM MQSeries background... but a stream is not a topic like I was used to

When a message is published to a subject, JetStream needs to know exactly which stream is responsible for persisting it. If two streams (e.g., ORDERS_US and ORDERS_ALL) both claimed the subject orders.new, NATS wouldn't know which retention policy, storage type, or acknowledgment logic to apply.

To prevent data duplication and logic conflicts, JetStream blocks any stream configuration that overlaps with a subject already assigned to another stream.

Overlaps aren't always identical matches; they often happen because of wildcards.

• Direct Overlap:
  Stream A: orders.us
  Stream B: orders.us (Error!)

• Wildcard Overlap:
  Stream A: orders.*
  Stream B: orders.us (Error! Stream A already covers this.)

• Sub-level Overlap:
  Stream A: orders.> (Matches everything starting with orders)
  Stream B: orders.processed (Error! Stream A has already "claimed" the entire orders hierarchy.)