Renxiang Zhou created FLINK-38131:
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Summary: Repartition BroadcastState with finished operators
Key: FLINK-38131
URL: https://issues.apache.org/jira/browse/FLINK-38131
Project: Flink
Issue Type: Bug
Components: Runtime / Checkpointing
Affects Versions: 1.14.0
Reporter: Renxiang Zhou
Fix For: 2.1.0
Attachments: image-2025-07-22-17-34-22-479.png
FLINK-23475 proposes how to distribute Broadcast state to new operator
instances to avoid new instances getting empty Broadcast state when there are
some finished operator in the DAG, and the task is restarted without changing
the parallelism. However, the current implementation seems to have some
problems in determining whether there is a finished operator.
As the pic shown below, `isPartiallyReported` compares the value between
BitSet's
`cardinality` and `size`, where `cardinality` represents the number of
operators that contain the Broadcast state, but `size` just returns the number
of bits of space actually in use by this BitSet. It makes no sense to compare
these two parameters, which causes the Broadcast state of operators without
finished status to be redistributed when the parallelism does not change, which
is unnecessary. I think we should use the `parallelism` in the constructor
instead of `reportedSubtaskIndices.size()`
!image-2025-07-22-17-34-22-479.png!
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