Sync to Async http request and response architecture
REST serviceClientProcessor microservices
(4).
Kafka (3)
All components are stateless (except Kafka, right?)
ClientREST serviceREST serviceProcessor msKafkaREST serviceProcessor msProcessor msREST serviceKafkaREST serviceClient within same http scope.
Now we decide to migrate (2) to microservice to take advantage of this architecture. And the problem occurred: instance 1 of (2) send command to (4), and (4) send the result to instance 2. But the http session is established between (1) and instance 1, and instance 2 cannot return to (1). This returning must be done by and only by instance 1.
My first idea is, for example, let instance 1 be aware of the result from (4) no matter it was sent to which instance. But currently we have no solution to archive this idea.
This is the diagram
<img class="content-img" src="https://stackask.com/wp-content/uploads/2022/12/Untitled.png" />
We need a "non work-around" solution for this architecture. Please help. Thank you
Note: we are unable to make change to blackbox components
