Edge case of order validation process in microservices-orders in at-least-once semantics

[tall15421542-lab]

Description
In microservices-orders example, we use numbers of validated OrderValidationResult in the topic to validate a order(ref) instead of the real rule matching.

It should be okay in the initial PR, which all producers and Kafka Streams are configured in exactly once semantics.
After this PR which add confluent interceptors, the processor now run in at least once semantic.

This should cause problem, for example, if we have

• 2 PASS OrderValidationResult from OrderDetailsService
• 1 PASS OrderValidationResult from inventoryService
• 1 FAIL OrderValidationResult from FraudService

We would send two Order with the same order id to the Orders topic, one with FAILED state and the other with VALIDATED state.

Troubleshooting
It's hard to reproduce the duplicate event delivery in local environment. All the above description is all from my inference. I am new to Kafka and Kafka Streams, so please kindly correct me if I am wrong.