cc850776b8
Proof'd everything and improved flow Renamed advanced to events Reordered sending/receiving Added text type to languages for prism plugin
1.9 KiB
Publish Subscribe
NATS implements a publish subscribe message distribution model as a one-to-many communication. A publisher sends a message on a subject and any active subscriber listening on that subject receives the message. Subscribers can also register interest in wildcard subjects that work a bit like a regular expression (but only a bit). NATS and NATS Streaming combine to offer two qualities of service:
-
At Most Once Delivery (NATS w/TCP reliability) - In the basic NATS platform, if a subscriber is not listening on the subject (no subject match), or is not active when the message is sent, the message is not received. NATS is a fire-and-forget messaging system. If you need higher levels of service, you can either use NATS Streaming, or build the additional reliability into your client(s) yourself.
-
At Least Once Delivery (NATS Streaming) - Some applications require higher levels of service and more stringent delivery guarantees but at the potential cost of lower message throughput and higher end-to-end delivery latency. These applications rely on the underlying messaging transport to ensure that messages are delivered to subscribers irrespective of network outages or whether or not a subscriber is offline at a particular point in time.
digraph nats_pub_sub {
rankdir=LR
publisher [shape=box, style="rounded", label="Publisher"];
subject [shape=circle, label="Subject"];
sub1 [shape=box, style="rounded", label="Subscriber"];
sub2 [shape=box, style="rounded", label="Subscriber"];
sub3 [shape=box, style="rounded", label="Subscriber"];
publisher -> subject [label="msg1"];
subject -> sub1 [label="msg1"];
subject -> sub2 [label="msg1"];
subject -> sub3 [label="msg1"];
}
Try NATS publish subscribe on your own, using a live server by walking through the pub-sub tutorial.