Upgrade considerations

OpenSSL 3.0.x upgrade in librdkafka requires a major version bump, as some legacy ciphers need to be explicitly configured to continue working, but it is highly recommended NOT to use them. The rest of the API remains backward compatible.

Enhancements

• References librdkafka.redist 2.0.2. Refer to the librdkafka v2.0.0 release notes and later ones for more information.
• Upgraded NJsonSchema to v10.6.3
• Added LatestCompatibilityStrict configuration property to JsonSerializerConfig to check the compatibility with latest schema when UseLatestVersion is set to true.
• Added DeleteConsumerGroupOffset to AdminClient.
• KIP-222 Finish remaining implementation: Add Consumer Group operations to Admin API (DeleteGroups is already present).
• KIP-518 Allow listing consumer groups per state.
• KIP-396 Partially implemented: support for AlterConsumerGroupOffsets.
• As result of the above KIPs, added (#1981)
  • ListConsumerGroups Admin operation. Supports listing by state.
  • DescribeConsumerGroups Admin operation. Supports multiple groups.
  • ListConsumerGroupOffsets Admin operation. Currently, only supports 1 group with multiple partitions. Supports the requireStable option.
  • AlterConsumerGroupOffsets Admin operation. Currently, only supports 1 group with multiple offsets.

Fixes

• During a group rebalance, partitions are now always revoked as a side effect of a call to Consume, whether or not a partitions revoked handler has been specified. Previously, if no handler was specified, the timing of when the consumer lost ownership of partitions during a rebalance was arbitrarily, frequently resulting in an erroneous state exception when committing or storing offsets.
• Fixed 100% CPU usage with DependentAdminClientBuilder.

Note: There were no 2.0.0 and 2.0.1 releases.