lianetm commented on code in PR #18756: URL: https://github.com/apache/kafka/pull/18756#discussion_r1947203398
########## docs/upgrade.html: ########## @@ -89,6 +89,27 @@ <h5><a id="upgrade_400_notable" href="#upgrade_400_notable">Notable changes in 4 </li> <li><b>Broker</b> <ul> + <li>The new Consumer Group Rebalance Protocol is now a production ready feature, enabled by default on the broker. + The supported group protocols are defined with the config <code>group.coordinator.rebalance.protocols=classic,consumer</code>, + with both protocols supported. Client applications should select the protocol to use (see Consumer section below). + <ul> + <li> + The supported partition assignment strategies are defined on the broker now, via the config <code>group.consumer.assignors</code>. + It defaults to <code>org.apache.kafka.coordinator.group.assignor.UniformAssignor</code>, so this will be the assignor used unless the consumer selects a different one (Consumer section below). + See <a href="https://cwiki.apache.org/confluence/pages/viewpage.action?pageId=217387038#KIP848:TheNextGenerationoftheConsumerRebalanceProtocol-AssignorSelection">Assignor selection</a> for more details. + </li> + <li> + Static membership behaviour changes to improve the experience and avoid conflicting members continuously affecting each other. + A static consumer trying to join a group with an instance ID that is already use will now fail with <code>org.apache.kafka.common.errors.UnreleasedInstanceIdException</code>. + The initial static consumer using the instance ID is not affected. + </li> + <li> + A new config <code>group.coordinator.threads</code> is added to control the number of threads used by the new group coordinator. + It defaults to 1, and it should be adjusted as needed. + See <a href="https://cwiki.apache.org/confluence/pages/viewpage.action?pageId=217387038#KIP848:TheNextGenerationoftheConsumerRebalanceProtocol-GroupCoordinator">New Group Coordinator</a> for more details. + </li> + </ul> + </li> Review Comment: makes sense, but should we add that on the GA notes linked better? -- This is an automated message from the Apache Git Service. To respond to the message, please log on to GitHub and use the URL above to go to the specific comment. To unsubscribe, e-mail: jira-unsubscr...@kafka.apache.org For queries about this service, please contact Infrastructure at: us...@infra.apache.org