Release Notes - Kafka - Version 2.6.1

Below is a summary of the JIRA issues addressed in the 2.6.1 release of Kafka. For full documentation of the release, a guide to get started, and information about the project, see the Kafka project site.

Note about upgrades: Please carefully review the upgrade documentation for this release thoroughly before upgrading your cluster. The upgrade notes discuss any critical information about incompatibilities and breaking changes, performance changes, and any other changes that might impact your production deployment of Kafka.

The documentation for the most recent release can be found at https://kafka.apache.org/documentation.html.

Improvement

• [KAFKA-10122] - Consumer should allow heartbeat during rebalance as well
• [KAFKA-10309] - KafkaProducer's sendOffsetsToTransaction should not block infinitively
• [KAFKA-10802] - Spurious log message when starting consumers

Bug

• [KAFKA-8033] - Flaky Test PlaintextConsumerTest#testFetchInvalidOffset
• [KAFKA-8630] - Unit testing a streams processor with a WindowStore throws a ClassCastException
• [KAFKA-9516] - Flaky Test PlaintextProducerSendTest#testNonBlockingProducer
• [KAFKA-9584] - Removing headers causes ConcurrentModificationException
• [KAFKA-9666] - Transactional producer Epoch could not be reset
• [KAFKA-10134] - High CPU issue during rebalance in Kafka consumer after upgrading to 2.5
• [KAFKA-10188] - Sink task preCommit method gets called after task is stopped
• [KAFKA-10218] - DistributedHerder's canReadConfigs field is never reset to true
• [KAFKA-10271] - Performance regression while fetching a key from a single partition
• [KAFKA-10282] - Log metrics are removed if a log is deleted and re-created quickly enough
• [KAFKA-10284] - Group membership update due to static member rejoin should be persisted
• [KAFKA-10332] - MirrorMaker2 fails to detect topic if remote topic is created first
• [KAFKA-10340] - Source connectors should report error when trying to produce records to non-existent topics instead of hanging forever
• [KAFKA-10387] - Cannot include SMT configs with source connector that uses topic.creation.* properties
• [KAFKA-10395] - TopologyTestDriver does not work with dynamic topic routing
• [KAFKA-10401] - GroupMetadataManager ignores current_state_timestamp field for GROUP_METADATA_VALUE_SCHEMA_V3
• [KAFKA-10426] - Deadlock in KafkaConfigBackingStore
• [KAFKA-10432] - LeaderEpochCache is incorrectly recovered on segment recovery for epoch 0
• [KAFKA-10439] - Connect's Values class loses precision for integers, larger than 64 bits
• [KAFKA-10454] - Kafka Streams Stuck in infinite REBALANCING loop when stream <> table join partitions don't match
• [KAFKA-10455] - Probing rebalances are not guaranteed to be triggered by non-leader members
• [KAFKA-10477] - Sink Connector fails with DataException when trying to convert Kafka record with empty key to Connect Record
• [KAFKA-10515] - NPE: Foreign key join serde may not be initialized with default serde if application is distributed
• [KAFKA-10531] - KafkaBasedLog can sleep for negative values
• [KAFKA-10557] - Missing docs when describing topic configs including documentation
• [KAFKA-10564] - Continuous logging about deleting obsolete state directories
• [KAFKA-10574] - Infinite loop in SimpleHeaderConverter and Values classes
• [KAFKA-10598] - KafkaStreams reports inappropriate error message for IQ
• [KAFKA-10600] - Connect adds error to property in validation result if connector does not define the property
• [KAFKA-10602] - DLQ Reporter throws NPE when reporting from different thread
• [KAFKA-10633] - Constant probing rebalances in Streams 2.6
• [KAFKA-10651] - Assignor reports offsets from uninitialized task
• [KAFKA-10705] - Avoid World Readable RocksDB
• [KAFKA-10706] - Liveness bug in truncation protocol can lead to indefinite URP
• [KAFKA-10755] - Should consider commit latency when computing next commit timestamp
• [KAFKA-10758] - Kafka Streams consuming from a pattern goes to PENDING_SHUTDOWN when adding a new topic
• [KAFKA-10811] - System exit from MirrorConnectorsIntegrationTest#testReplication

Test

• [KAFKA-10404] - Flaky Test kafka.api.SaslSslConsumerTest.testCoordinatorFailover