riyaverm-db opened a new pull request, #46942:
URL: https://github.com/apache/spark/pull/46942
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### What changes were proposed in this pull request?
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The changes include adding a `deepCopy()` method to **RocksDBFileManager**,
and adding respective test case to check if private concurrent hash maps
defined in the class were deep copied successfully. Additionally, we use this
deep copy method when loading a previous version, and capture the reference to
the file manager in `commit()`.
### Why are the changes needed?
Currently the lock of the RocksDB state store is acquired when uploading the
snapshot inside maintenance tasks when change log checkpointing is enabled,
which causes lock contention between query processing tasks and state
maintenance thread. To eliminate the lock contention, lock acquisition inside
maintenance tasks should be avoided. To prevent race conditions between task
and maintenance threads, we can ensure that RocksDBFileManager has a linear
history by ensuring a deep copy of RocksDBFileManager every time a previous
version is loaded. The original file manager is not affected by future state
update. The new file manager is not affected by background snapshot uploading
tasks that attempt to upload a snapshot.
### Does this PR introduce _any_ user-facing change?
No
### How was this patch tested?
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WIP
### Was this patch authored or co-authored using generative AI tooling?
No
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