The `PartitionGrouper` interface was originally exposed to allow user a higher degree of flexibility with regard to partition to task mapping. However, Kafka Streams runtime employs many undocumented restrictions to write a correct `PartitionGrouper` and hence it is easy for users to break the runtime that way.
In practice, we have not seen the usage of the interface. Hence, we should consider to deprecate and eventually remove it.
- is related to
KAFKA-7785 Remove PartitionGrouper interface and it's config and move DefaultPartitionGrouper to internal package
KAFKA-10046 Deprecated PartitionGrouper config is ignored
- links to