Hi Samy, If I understand your question correctly, you're looking for a way to retrieve a value based on a corresponding key. That would require you to build an index. Kafka can look up records based on the record time, but by default will not build any kind of index based on the record key. In fact, the keys are opaque to the broker. It just sees them as a bag of bytes and does not try to interpret what they mean.
You might want to check out the state store functionality in Kafka Streams. See: http://docs.confluent.io/3.1.0/streams/developer-guide.html#querying-local-state-stores-for-an-application-instance Another approach would be to feed your kafka stream into a database of some kind and do queries against the database. regards, Colin On Tue, Feb 14, 2017, at 08:42, Samy CHBINOU wrote: > In kafka there is a Subscribe API to be notified of incoming message > values from a topic. I didn't see a Get(key, topic) function. I mean a > Get function to retreive a value from a key inside a topic. Isn't this > feature implemented? (Like in Redis). If it doesn't exists, do you think > is is easy to implement? > Best Regard
