I’m joining two streams - one is a “decoration” stream that we have in a compacted Kafka topic, produced using a view on a MySQL table AND using Kafka Connect; the other is the “event data” we want to decorate, coming in over time via Kafka. These streams are keyed the same way - via an “id” field, and we join them using CoFlatMap that attaches the data from the decoration stream to the event data and publishes downstream.
What I’d like to do in my CoFlatMap is wait to process the event data until we’ve received the corresponding decoration data. How do I make that happen? Alternatively, is there another structure that will work to prevent non-decorated event data from being allowed through until the corresponding decoration event appears? Thanks! Ron
