GitHub user ernisv opened a pull request:
https://github.com/apache/storm/pull/1873
Kafka spout - no duplicates on leader changes
Current behavior of Kafka spout emits duplicate tuples whenever Kafka topic
leader's change.
In case of exception caused by leader changes, PartitionManagers are simply
recreated losing the state about which tuples were already emitted and new
PartitionManager re-emits them again.
This is fine as at-least-once is fulfilled, but still it would be better to
not emit duplicate data if possible.
Moreover this could be easily avoided by moving the state related to
emitted tuples from old PartitionManager to new one.
You can merge this pull request into a Git repository by running:
$ git pull https://github.com/ernisv/storm
kafka_spout_no_dup_on_leader_changes
Alternatively you can review and apply these changes as the patch at:
https://github.com/apache/storm/pull/1873.patch
To close this pull request, make a commit to your master/trunk branch
with (at least) the following in the commit message:
This closes #1873
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commit 9b1e336ed03a320b25e5799655eb64571ce21c48
Author: Ernestas Vaiciukevicius <[email protected]>
Date: 2017-01-12T14:54:59Z
Move state from old PartitionManager when recreating manager for same
partition
commit a1a7cef9c84941ef8a1909fd4db10c85fe509e0e
Author: Ernestas Vaiciukevicius <[email protected]>
Date: 2017-01-12T15:39:51Z
Test to check if old PartitionManager's state is moved to new manager
during manager recreate
commit c8c6ee83d69cf76d8aaeb9d5ccaedbd5946d4c9b
Author: Ernestas Vaiciukevicius <[email protected]>
Date: 2017-01-12T15:57:46Z
Include _emittedToOffset when copying state during PartitionManager recreate
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