"keyed" aggregation

Posted by Christophe Jolif on
URL: http://deprecated-apache-flink-user-mailing-list-archive.369.s1.nabble.com/keyed-aggregation-tp17641.html

Hi all,

I'm sourcing from a Kafka topic, using the key of the Kafka message to key the stream, then doing some aggregation on the keyed stream.

Now I want to sink back to a different Kafka topic but re-using the same key. The thing is that my aggregation "lost" the key. Obviously I can make sure my aggregation function keeps the key, but I find that a bit strange as it does not relate to aggregation.

Is there a best practice in that domain? How should the key be carried when moving from a kafka source to sink but doing some aggregation along the way?

Thanks,

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