TakaHiR07 opened a new issue, #23027: URL: https://github.com/apache/pulsar/issues/23027
### Search before asking - [X] I searched in the [issues](https://github.com/apache/pulsar/issues) and found nothing similar. ### Motivation As the code shown, even if we disable txn, we use topic.getMaxReadPosition() which is topic.lastConfirmedEntry as OpReadEntry's maxPosition. However, there exist the situation: 1. create OpReadEntry, using current topic's lastConfirmedEntry 2. cursor hasNoMoreEntry, addWaitingCursor. opReadEntry become waiting. 3. topic add new entry, trigger notifyEntriesAvailable() to notify opReadEntry 4. Since opReadEntry.maxPosition is the previous lastConfirmedEntry, and now the lastConfirmedEntry has been changed. This op would enter opReadEntry.checkReadCompletion and trigger callback directly without reading any entry. 5. Therefore, it would cause one more time to execute readEntry request. So this is where we can improve, actually we may be able to execute the opReadEntry directly. By the way, in version-2.9, if we disable txn, topic.getMaxReadPosition() is Position.latest, so opReadEntry.maxPosition is Position.latest too. And it would not have this issue since op.maxPosition is always > op.readPosition. https://github.com/apache/pulsar/blob/c160cc9c3d44c1df073d63b325b45b9bc9bff8c7/pulsar-broker/src/main/java/org/apache/pulsar/broker/transaction/buffer/impl/TransactionBufferDisable.java#L109-L113 https://github.com/apache/pulsar/blob/c160cc9c3d44c1df073d63b325b45b9bc9bff8c7/pulsar-broker/src/main/java/org/apache/pulsar/broker/service/persistent/PersistentDispatcherSingleActiveConsumer.java#L368-L381 https://github.com/apache/pulsar/blob/5dc030431a60b49e81d577cd06a1ae63dbee0293/managed-ledger/src/main/java/org/apache/bookkeeper/mledger/impl/ManagedCursorImpl.java#L934-L979 https://github.com/apache/pulsar/blob/5dc030431a60b49e81d577cd06a1ae63dbee0293/managed-ledger/src/main/java/org/apache/bookkeeper/mledger/impl/ManagedLedgerImpl.java#L2051-L2056 https://github.com/apache/pulsar/blob/5dc030431a60b49e81d577cd06a1ae63dbee0293/managed-ledger/src/main/java/org/apache/bookkeeper/mledger/impl/OpReadEntry.java#L164-L186 ### Solution Update the opReadEntry.maxPosition when trigger notifyEntriesAvailable() ### Alternatives _No response_ ### Anything else? _No response_ ### Are you willing to submit a PR? - [X] I'm willing to submit a PR! -- 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: commits-unsubscr...@pulsar.apache.org.apache.org For queries about this service, please contact Infrastructure at: us...@infra.apache.org
