BewareMyPower opened a new pull request, #18486: URL: https://github.com/apache/pulsar/pull/18486
### Motivation https://github.com/apache/pulsar/pull/18454 fixed the potential message loss when a batched message is redelivered and one single message of the batch is added to the ACK tracker. However, it also leads to a potential message duplication, see the `testConsumerDedup` test modified by #18454. The root cause is that single messages will still be passed into the `isDuplicated` method in `receiveIndividualMessagesFromBatch`. However, in this case, the `MessageId` is a `BatchedMessageIdImpl`, while the `MessageId` in `lastCumulativeAck` or `pendingIndividualAcks` are `MessageIdImpl` implementations. ### Modifications Validate the class type in `isDuplicated` and convert a `BatchedMessageIdImpl` to `MessageIdImpl`. Then revert the unnecessary changes in #18454. `ConsumerRedeliveryTest#testAckNotSent` is added to verify it works. ### TODO The duplication could still happen when batch index ACK is enabled. Because even after the ACK tracker is flushed, if only parts of a batched message are not acknowledged, the whole batched message would still be redelivered. I will open another PR to fix it. ### Documentation <!-- DO NOT REMOVE THIS SECTION. CHECK THE PROPER BOX ONLY. --> - [ ] `doc` <!-- Your PR contains doc changes. Please attach the local preview screenshots (run `sh start.sh` at `pulsar/site2/website`) to your PR description, or else your PR might not get merged. --> - [ ] `doc-required` <!-- Your PR changes impact docs and you will update later --> - [x] `doc-not-needed` <!-- Your PR changes do not impact docs --> - [ ] `doc-complete` <!-- Docs have been already added --> ### Matching PR in forked repository PR in forked repository: https://github.com/BewareMyPower/pulsar/pull/8 -- 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: [email protected] For queries about this service, please contact Infrastructure at: [email protected]
