It would be useful to be explicit about the Subscribe step in Pub/Sub

KeithDuddyS23M commented 5 months ago

Summary

In the Publish/Subscribe pattern, only the case where the consumers (subscribers) of messages are already set up. I think it's worth saying something briefly about the step of the interested API Consumers communicating their subscription (and later possibly un-subscription) to the channel of interest at the Broker, and the Broker then keeping it on a list of subscribers, then delivering messages (as already described) until an un-subscribe request is made, at which point the API Consumer is removed from the list.

Link to standards item

https://apistandards.digital.health.nz/api-development/Asynchronous%20APIs/Async%20Patterns/PubSub

Which area of the standards does this apply to?

[ ] Part A - API Concepts
[ ] Part B - API Security
[X] Part C - API Design and Development
[ ] Part D - FHIR
[ ] Community guidelines

mathusmith commented 4 months ago

@KeithDuddyS23M there is a more detailed description of subscription handling . I do agree though that the pattern description would benefit from a mention of subscriptions by consumers.

KeithDuddyS23M commented 4 months ago

Thanks @mathusmith ... I didn't know that I missed that Subscription/Topic section.This is strange, because even though I sometimes make comments when I don't realise that things are coming later, this precedes the Patters section. And now I'm trying to follow David Moon's suggested review procedure of scanning all the content before commenting on specifics. Maybe it was inserted at v1.2, and I had commented on v1.1). However, given the example diagrams in the Topics/Subscriptions, I think this covers my concerns (although a cross-reference might be good).

cheers, K

tewhatuora / api-standards