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2) Add a new configuration setting to MirrorMaker:

Name: enable.incremental.alter.configs

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4) From Kafka 4.0, syncTopicConfigs() will only call  updateTopicConfigsUsingIncrementalAlterConfigs() by default. The existing updateTopicConfigs() will be removed.

Compatibility, Deprecation, and Migration Plan

By default, the new setting will be set to false so it does not change the current behaviour. This setting will be marked as deprecated immediately. 

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(Is it necessary to add system tests)

Rejected Alternatives

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• We could have changed the current updateConfigs() method to call describeConfigs API before alterConfigs so that it had an incremental mode. This would have avoided migrating to incrementalAlterConfigs API and adding a new configuration setting to MirrorMaker.  However, the topics configurations could change between describeConfigs and alterConfigs calls so we could still end up applying incorrect topic configurations. We would need to stop using the  deprecated API at some point anyway.