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• Update producer to send the header value in all record.
• Roll out the producer first to all clusters.
• Once all producers sending the header value confirmed, update the topic config on the broker side with the header strategy.
• Note:
  • any existing topic migration, the already compacted log still remains as such (i.e. offset based) and only the new logs will get compacted using the new strategy once the topic config updated with the strategy.
  • in any case if topic strategy needs roll back to default offset strategy, first topic config on the broker side should be updated to offset strategy and then producer can stop generating the header value.

Recommendations

• For scenarios like the low produce rate, the topic partition remaining ineligible for compaction for an unbounded duration where by "delete.retention.ms" triggers that removes the tombstone record if exist. In that case we recommend the Kafka users to have "segment.ms" & "max.compaction.lag.ms" (as compaction won't happen on active segment) to be smaller than the "delete.retention.ms".
• As this KIP is introducing configurable compaction strategy, the Consumer should be aware and follow the same compact strategy as in broker to avoid inconsistency on what records to keep.

Rejected Alternatives

      (This section remains the same as previous proposal.)

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