Page History

...

1. Every time a protocol version changes, for any request/response, ApiVersion will be bumped up.
2. Protocol documentation will be versioned with ApiVersion. Every time there is a ApiVersion change, protocol documentation version needs to be updated and linked to main documentation page.
3. Deprecation of protocol version will be done via marking the version as deprecated on the protocol documentation.
4. On getting unknown protocol version, broker will send an empty response, instead of simply closing client connection.
5. Metadata response will be enhanced to also contain broker version, i.e., (versionId, versionString), of the responding broker.
6. Metadata request with single null topic and size of -1 a null array can be used to fetch metadata response with only broker version information and no topic/broker info. Note that this will require changing MetadataRequest from ArrayOf[STRING] to NullableArrayOf[STRING].
7. On receiving a metadata request with single null topic with size of -1null array, broker will respond without topics metadata, as this can lead to unnecessary penalty on large clusters.

...