Hacker News Reader

That polling endpoint is a message bus, just disguised as a REST endpoint.

You point about the SPOF is that you prefer distributed state inside the individual services over having events stored in the message bus? Then you're back to high coupling between the inventory manager and notifier, if the former is down the latter won't be able to send out any notifications.

View on HN

If the inventory manager is down, no updates to the stock can occur, so what notifications are there to be sent? You can't eliminate coupling that arises from the semantics of the model, only obscure it by adding a layer of indirection.

The coupling that should be eliminated is the reverse, ie., the inventory being unable to update stock if the notifier is down, which the article claimed was inevitable using REST. I tried to show it isn't.

Regarding the message bus, I actually meant the broker, which is the SPOF being introduced in the proposed architecture.

Reply on news.ycombinator.com