KIP-306 — Configuration for Delaying Response to Failed Authentication

Accepted Kafka 2.1 SecurityBroker

Adds a `connection.failed.authentication.delay.ms` broker config that delays the error response to a client that fails authentication, throttling brute-force and misconfigured reconnect storms. A misconfigured application reconnecting with invalid credentials can saturate broker network threads with authentication work, causing a denial-of-service for legitimate clients.

Details