sarutak opened a new pull request #33818:
URL: https://github.com/apache/spark/pull/33818


   ### What changes were proposed in this pull request?
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   This PR fixes an issue that executors are never re-scheduled if the worker 
which the executors run on stops.
   As a result, the application stucks.
   You can easily reproduce this issue by the following procedures.
   
   ```
   # Run master
   $ sbin/start-master.sh
   
   # Run worker 1
   $ SPARK_LOG_DIR=/tmp/worker1 SPARK_PID_DIR=/tmp/worker1/ 
sbin/start-worker.sh -c 1 -h localhost -d /tmp/worker1 --webui-port 8081 
spark://<hostname>:7077
   
   # Run worker 2
   $ SPARK_LOG_DIR=/tmp/worker2 SPARK_PID_DIR=/tmp/worker2/ 
sbin/start-worker.sh -c 1 -h localhost -d /tmp/worker2 --webui-port 8082 
spark://<hostname>:7077
   
   # Run Spark Shell
   $ bin/spark-shell --master spark://devel-extreme:7077 --executor-cores=1 
--total-executor-cores 1
   
   # Check which worker the executor runs on and then kill the worker.
   $ kill <worker pid>
   ```
   
   With the procedure above, we will expect that the executor is re-scheduled 
on the other worker but it won't.
   
   The reason seems that `Master.schedule` cannot be called after the worker is 
marked as `WorkerState.DEAD`.
   So, the solution this PR proposes is to call `Master.schedule` whenever 
`Master.removeWorker` is called.
   
   This PR also fixes an issue that `ExecutorRunner` can send 
`ExecutorStateChanged` message without changing its state.
   This issue causes assertion error.
   ```
   2021-08-13 14:05:37,991 [dispatcher-event-loop-9] ERROR: Ignoring 
errorjava.lang.AssertionError: assertion failed: executor 0 state transfer from 
RUNNING to RUNNING is illegal
   ```
   
   ### Why are the changes needed?
   <!--
   Please clarify why the changes are needed. For instance,
     1. If you propose a new API, clarify the use case for a new API.
     2. If you fix a bug, you can clarify why it is a bug.
   -->
   It's a critical bug.
   
   ### Does this PR introduce _any_ user-facing change?
   <!--
   Note that it means *any* user-facing change including all aspects such as 
the documentation fix.
   If yes, please clarify the previous behavior and the change this PR proposes 
- provide the console output, description and/or an example to show the 
behavior difference if possible.
   If possible, please also clarify if this is a user-facing change compared to 
the released Spark versions or within the unreleased branches such as master.
   If no, write 'No'.
   -->
   No.
   
   ### How was this patch tested?
   <!--
   If tests were added, say they were added here. Please make sure to add some 
test cases that check the changes thoroughly including negative and positive 
cases if possible.
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how you tested step by step, ideally copy and paste-able, so that other 
reviewers can test and check, and descendants can verify in the future.
   If tests were not added, please describe why they were not added and/or why 
it was difficult to add.
   -->
   Manually tested with the procedure shown above and confirmed the executor is 
re-scheduled.


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