"A Publish-Subscribe Channel works like this: It has one input channel that splits into multiple output channels, one for each subscriber. When an event is published into the channel, the Publish-Subscribe Channel delivers a copy of the message to each of the output channels. Each output channel has only one subscriber, which is only allowed to consume a message once. In this way, each subscriber only gets the message (at-most in the case of gnatsd) once and consumed copies disappear from their channels. "
To demonstrate NATS publish/subscribe.
-
Get and run nats-sub:
go get github.com/nats-io/go-nats-examples/tools/nats-sub nats-sub -s demo.nats.io some_subject -
Get and run nats-pub:
go get github.com/nats-io/go-nats-examples/tools/nats-pub nats-pub -s demo.nats.io some_subject message -
Verify publisher output:
Published [subject_name] : 'message' -
Verify subscriber output:
Listening on [subject_name] [#1] Received on [channel_name]: 'message' -
Optionally install your own server:
go get github.com/nats-io/nats-server; nats-server &