The meaning of 'request.timeout.ms' of Kafka producer makes me confused

Question

Well, I find that the meaning of request.timeout.ms of Kafka 0.8.2 differs from Kafka 0.10.0.

https://kafka.apache.org/082/documentation.html

https://kafka.apache.org/documentation/

Kafka 0.8.2: request.timeout.ms The amount of time the broker will wait trying to meet the request.required.acks requirement before sending back an error to the client.

Kafka 0.11.0: request.timeout.ms The configuration controls the maximum amount of time the client will wait for the response of a request. If the response is not received before the timeout elapses the client will resend the request if necessary or fail the request if retries are exhausted.

Answer 1

In Kafka 0.8.2 the request.timeout.ms is related to the producer. As you know the producer chose to receive the ack in three different cases : when just sent, when leader receives and writes message, when leader and all replicas receive and write message. The timeout is the time a broker waits one of the above condition (for sending ack to producer) before sending an error : the ack can't be sent on time and timeout expires. In Kafka 0.11 this timeout is more general and used even for consumer and admin client : it's the timeout for a generic request and not strictly related to write message.