Is Kafka Stream StateStore global over all instances or just local?

Question

In Kafka Stream WordCount example, it uses StateStore to store word counts. If there are multiple instances in the same consumer group, the S

Answer 1

If worth mentioning that there is a GlobalKTable improvement proposal

GlobalKTable will be fully replicated once per KafkaStreams instance. That is, each KafkaStreams instance will consume all partitions of the corresponding topic.

From the Confluent Platform's mailing list, I've got this information

You could start prototyping using Kafka 0.10.2 (or trunk) branch...

0.10.2-rc0 already has GlobalKTable!

Here's the actual PR.

And the person that told me that was Matthias J. Sax ;)