JetStream NATSNoRespondersException

[Walluce]

Question about NATSNoRespondersException behaviour.

We are considering using NATS and JetStream for inter component communication.

I had assumed that if I write a message to a stream, it will get saved on the stream for consumer to pick up later (like Kafka). Instead I am getting an exception.

What I am concerned about is the use-case where all of my consumers are stopped / fall over. I would not like to lose messages because the consumer can't produce any more.

What am I doing wrong?

[scottf]

@Walluce No Responders means the server cannot find any stream with the subject you are publishing to. What is your stream configuration and what subject are you publishing to?

[Walluce]

Hi, @scottf,
The stream name is "users"
The subjects specified when I created the stream was "users.*"
The subject of the message I am publishing is "users.logoff.[random integer]"

I am trying to set up Deterministic Token Partitioning

This is my config file:

mappings: {
    foo : bar
    "users.logoff.*" : "users.logoff.{{wildcard(1)}}.{{partition(10,1)}"
    "neworders.*" : "neworders.{{wildcard(1)}}.{{partition(3,1)}}"
}

[scottf]

I see the problem. The *, only represents one segment. So users.* only allows for users.a not users.a.b
If you specify users.> as your stream subject, you will be fine. You could I think specify users.*.*

Here is the documentation for subjects https://docs.nats.io/nats-concepts/subjects#subject-hierarchies

[Walluce]

Thank you, that solved my problems.