JingsongLi commented on PR #8855:
URL: https://github.com/apache/paimon/pull/8855#issuecomment-5088794924

   Could we avoid interrupting workers that have already finished reading and 
are only closing their readers?
   
   `latch.countDown()` happens before the try-with-resources closes the 
iterator. Therefore, after `take()` observes completion, the worker may still 
be inside `RecordReader.close()`. Calling `shutdownNow()` here interrupts that 
cleanup. `awaitTermination()` then only guarantees that the worker exited; it 
does not guarantee that cleanup completed successfully.
   
   I reproduced this with a reader whose `close()` waits on an interruptible 
semaphore. `ParallelExecution.close()` interrupted the cleanup and returned 
before the semaphore was released, with the cleanup operation never completed. 
The new test uses `acquireUninterruptibly()`, so it cannot expose this race.
   
   For the normal completed-read path, could we use 
`executorService.shutdown()` when `latch.getCount() == 0`, and reserve 
`shutdownNow()` for early cancellation? Alternatively, moving the countdown 
after resource cleanup would also avoid this race.
   


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