[flink] Remove Flink state from write-only writers #4185
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wwj6591812
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Sep 14, 2024
| @@ -52,37 +55,54 @@ public TableWriteOperator( | |||
| this.initialCommitUser = initialCommitUser; | |||
| } | |||
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| private boolean needState() { | |||
| if (table.coreOptions().writeOnly()) { | |||
| // Commit user for writers are used to avoid conflicts. | |||
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But users may use the commit user to determine if a table's snapshot is generated by the other job. See : #3474
So, I think you can add a config for users to decide whether they need the commitUser state (default true). And explain in the doc that in bounded stream scenarios, if this configuration is true, there will be side effects(when chaining source and write operator together, if some source parallelism have finished, checkpoint cannot be performed).
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This commitUser is only for writers. What you have mentioned is the commitUser for comitters.
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+1 |
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Closing because write-only writers should also wait for snapshot. They need to read latest |
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Purpose
Currently Paimon writer operators in Flink have states, which record the
commitUser(for all writers) and the list of active buckets (for lookup or full-compaction changelog producer). These states prevent a writer object to be closed too early and cause conflicts.However for write-only writers, because they only create new files, there is no conflict. So for these writers we can remove Flink state. This optimization is also useful for bounded stream jobs, because when chaining source and write operator together, if some source parallelism have finished, checkpoint cannot be performed if there are union list states in the operators which are still running.
Tests
Existing tests should cover this change.
API and Format
No format changes.
Documentation
No new feature.