A message / event bus
At http://localhost:8222/streaming.
See subscribers list and details for channels : http://localhost:8222/streaming/channelsz?subs=1
Queue groups are made so several instances of a listener don't receive several times the same message / event.
In short, if you have two instances of one listener "A", and if you set up a queue group, the message / event will go to one instance and not the other one.
This is really useful, because it allow to get rid off event duplication for a same listener, which would have conducted to a double-processing.
Ex : on event received, the listener/app push to db. With 2 instances of your listener, it would push twice to db.
hb (for hardbit) is basically an healthcheck.
hbi: how often a healthcheck request is made to client by NATS SShbt: how long each client has to respondhbf: number of times each client can fail before NATS SS assumes that the connection is dead and gone