CODEWITHSUNDEEP
microservices
Jordi
Jordi

Reputation: 23207

Asynchronously communication between clients and services

I've been reading for some tome ago about "asynchronous communication between microservices" and its benefits.

Something doesn't fit on my mind:

  1. What about if client only is able to make synchronous communicacion to my service?
  2. Or what about, if service has to be able to dispath both synchro and asynchro communication?

I mean, I can design a "barista system" like this:

Dispatchning an event from "counter service" and send a "coffee is ready" to client, when "counter service" receive an "coffee is ready event" from "barista service".

Some counterparts here:

  1. How "counter service" sends feedback to client? Request connection has been release and then server is not able to point to client.
  2. What about if client are not able to treat with asynchromously communiations?

I mean, what about if client is only able to handle synchronous communication on a "asynchronously inter-service communication"?

Which feedback techniques are available here? I mean, are there more modern techniques besides of "polling request status"?

Upvotes: 1

Views: 178

Answers (1)

Levi Ramsey
Levi Ramsey

Reputation: 20551

If a client is only able to communicate synchronously (i.e. no interaction besides client makes request and then client gets response is possible), then you essentially have two options:

  • You can respond to the initial request with some unique identifier that the client can use to request a [more] final response. In the coffee bar example, this would be like placing an order over the phone, being told an order number, coming into the shop at some later point, and asking "is order XYZ ready?". This is fairly lightweight, at least as long as the client doesn't just spam you with request updates (as in rapid polling).

  • Alternatively, you can present a synchronous API even if the internals are asynchronous: you just need a component that holds the interaction open until the response is final. The analogy here would be if an order is placed over the phone, the order taker is required to stay on the line with the customer until the customer comes in to pick up the coffee. If the connection breaks, the coffee is lost.

Upvotes: 1

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