@cats-cradle/message-broker NPM

@cats-cradle/message-broker

This is a “Pub/Sub Message Broker”. It enables async communication between microservices to provide loosely coupling.

SNS topics are deployed with the message broker.
SQS deployments should be owned by consumer.

Message Categories

Command Command send a idempotent request to a topic asking subscribers to perform task. The consumer of a command does not inform provide a response to the publisher. The publisher does expect something to occur as a result of the request.

Publisher -> SNS -> SQS -> Consumer

Event Publish to a SNS topic informing any subscribers that something occurred within a given system. Events published may be significant events that were published only for the purpose of data retention and analytic purposes.

Publisher -> SNS -> SQS -> Consumer

Request Publish an async message to a single queue letting them know which queue to send a reply to.

Publisher -> SQS -> Consumer -> (SQS -> Publisher)

Reply In response to a request publish an message to a single queue as request.

(Publisher -> SQS) -> Consumer -> SQS -> Publisher

TODO

Add a feature to make it easy for apps to publish to events.
Add a feature to make it easy to subscribe to events.
Provision S3 bucket and place all history of all events into.
Save all messages received to bucket.
Indicate whether message was sent only for testing / debugging purposes and should not contaminate history.
Hydration that ties into api-client query might be nifty.
logical id format
decouple topics from broker into global lib

@cats-cradle/message-broker v1.0.0