Lucas Bradstreet created KAFKA-9577: ---------------------------------------
Summary: Client encountering SASL_HANDSHAKE protocol version errors on 2.5 / trunk Key: KAFKA-9577 URL: https://issues.apache.org/jira/browse/KAFKA-9577 Project: Kafka Issue Type: Bug Components: core Affects Versions: 2.5.0 Reporter: Lucas Bradstreet I am trying 2.5.0 with sasl turned on and my consumer clients receive: {noformat} org.apache.kafka.common.errors.UnsupportedVersionException: The SASL_HANDSHAKE protocol does not support version 2 {noformat} I believe this is due to [https://github.com/apache/kafka/commit/0a2569e2b9907a1217dd50ccbc320f8ad0b42fd0] which added flexible version support and bumped the protocol version. It appears that the SaslClientAuthenticator uses the max version for SASL_HANDSHAKE returned by the broker's api versions request, and then uses that version even though it may not support it. See [https://github.com/apache/kafka/blob/eb09efa9ac79efa484307bdcf03ac8eb8a3a94e2/clients/src/main/java/org/apache/kafka/common/security/authenticator/SaslClientAuthenticator.java#L290]. This may make it hard to ever evolve this schema. In the short term I suggest we roll back the version bump and flexible schema until we figure out a path forward. -- This message was sent by Atlassian Jira (v8.3.4#803005)