Fixed dispatcher skipping delivery of a batch during concurrent replays #5499
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This issue apparently was introduced in #5391 |
jerrypeng
approved these changes
Oct 29, 2019
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rerun java8 tests |
run java8 tests |
sijie
approved these changes
Oct 30, 2019
wolfstudy
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Nov 20, 2019
…ys (#5499) There is a race condition when replaying messages on the `PersistentDispatcherMultipleConsumers`. This is apparently only happening in the context of delivering messages after a scheduled delay. The `Dispatcher.readMoreEntries()` can get invoked in multiple occasions: * Piggybacking on the completion of the previous read operation * When the delaye tracker gets triggered If there is already a replay read operation pending, we're currently ignoring the message ids returned by the delay tracker. These messages will not be retried on any other occasion, leading to backlog building up (until a consumer disconnects/reconnects). (cherry picked from commit 01ca24b)
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Motivation
There is a race condition when replaying messages on the
PersistentDispatcherMultipleConsumers. This is apparently only happening in the context of delivering messages after a scheduled delay.The
Dispatcher.readMoreEntries()can get invoked in multiple occasions:If there is already a replay read operation pending, we're currently ignoring the message ids returned by the delay tracker. These messages will not be retried on any other occasion, leading to backlog building up (until a consumer disconnects/reconnects).
Modifications
If we know we have a pending replay operation, don't fetch message ids from the delay tracker.