[KAFKA-9529] Request Header v0 inconsistent between documentation and implementation

• Type: Bug
• Status: Open
• Priority: Minor
• Resolution: Unresolved
• Component/s: documentation
• Assignee: Unassigned
• Reporter: Diggory James Joshua Blake
• Created: 09/Feb/20 18:34
• Updated: 09/Feb/20 18:34

Description

The protocol documentation specifies Request Header v0 like this:

Request Header v0 => request_api_key request_api_version correlation_id 
  request_api_key => INT16
  request_api_version => INT16
  correlation_id => INT32

With the `client_id` field only being added in Request Header v1.

However, Kafka will error on any request without the `client_id` even if the client sets the API version to zero. Also, the JSON files specify that `client_id` has been present since version zero:

https://github.com/apache/kafka/blob/e24d0e22abb0fb3e4cb3974284a3dad126544584/clients/src/main/resources/common/message/RequestHeader.json#L27