1.发布时间

KIP Freeze时间：2019年1月24日

Feature Freeze时间：2019年1月31日

Code Freeze时间：2019年2月15日

Release时间：2019年3月22日

2.版本需求

Kafka2.2.0版本对以下18个特性进行了开发。

KIP-183 - Change PreferredReplicaLeaderElectionCommand to use AdminClient

KIP-207: Offsets returned by ListOffsetsResponse should be monotonically increasing even during a partition leader change

KIP-289: Improve the default group id behavior in KafkaConsumer

KIP-291: Separating controller connections and requests from the data plane

KIP-313: Add KStream.flatTransform and KStream.flatTransformValues

KIP-367 Introduce close(Duration) to Producer and AdminClient instead of close(long, TimeUnit)

KIP-368: Allow SASL Connections to Periodically Re-Authenticate

KIP-371: Add a configuration to build custom SSL principal name

KIP-374: Add '--help' option to all available Kafka CLI commands

KIP-376: Implement AutoClosable on appropriate classes that want to be used in a try-with-resource statement

KIP-377: TopicCommand to use AdminClient

KIP-380: Detect outdated control requests and bounced brokers using broker generation

KIP-386: Standardize on Min/Avg/Max metrics' default value

KIP-389: Introduce a configurable consumer group size limit

KIP-393: Time windowed serde to properly deserialize changelog input topic

KIP-394: Require member.id for initial join group request

KIP-414: Expose Embedded ClientIds in Kafka Streams

KIP-420: Add Single Value Fetch in Session Stores