MINOR: add upgrade not for group.initial.rebalance.delay.ms
Add a new entry in upgrade.html for `group.initial.rebalance.delay.ms`
Author: Damian Guy
Reviewers: Ismael Juma Guozhang Wang
Closes from dguy/relabance-delay
<li>Added user headers support through a new Headers interface providing user headers read and write access.</li>
<li>ProducerRecord and ConsumerRecord expose the new Headers API via <code>Headers headers()</code> method call.</li>
<li>ExtendedSerializer and ExtendedDeserializer interfaces are introduced to support serialization and deserialization for headers. Headers will be ignored if the configured serializer and deserializer are not the above classes.</li>
+ <li>A new config,<code>group.initial.rebalance.delay.ms</code>, was introduced.
+ This config specifies the time, in milliseconds, that the <code>GroupCoordinator</code> will delay the initial consumer rebalance.
+ The rebalance will be further delayed by the value of <code>group.initial.rebalance.delay.ms</code> as new members join the group, up to a maximum of <code>max.poll.interval.ms</code>.
+ The default value for this is 3 seconds.
+ During development and testing it might be desirable to set this to 0 inorder to not delay test execution time.
+ </li>
</ul>
<h5><a id="upgrade_1100_new_protocols" href="#upgrade_1100_new_protocols">New Protocol Versions</a></h5>
