How to notify the user when the registration is completed

Imported from Google Groups
1

Hi All

I am creating an event and microservices-based e-commerce application. In a traditional monolithic architecture, the registration flow is very simple. Users enter data - > data gets validated - > registration successful message.

How to implement this in AXON since the command flow is separated from query flow and event processing is totally asynchronous. If the UI is calling the create customer microservice in the customer app, it returns immediately and maybe with the aggregate Id for the customer. But how to notify customers that that registration has been successful? What is the solution pattern here?

Thanking you in advance.
Rajib

2

I think you would have to do something like push down to the client (websocket type of approach), or possibly have the client polling to check when the registration completed.

3

In this case it seems like you need a “subscription query”.

Check out the project here: https://github.com/idugalic/digital-restaurant

And also search for pages about Axon’s subscription query.

The idea is to give the illusion of being synchronous to the user by subscribing to a change that would occur once your command is run.

Here is a direct link to some code which uses it: https://github.com/idugalic/digital-restaurant/blob/master/drestaurant-apps/drestaurant-microservices-rest/drestaurant-microservices-rest-courier/src/main/kotlin/com/drestaurant/web/CommandController.kt

4

This is what I was looking for. - Thank you