[jira] [Created] (FLINK-14859) Avoid leaking unassigned Slot in DefaultScheduler when Deployment is outdated

[Shang Yuanchun (Jira)]

Gary Yao created FLINK-14859:
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             Summary: Avoid leaking unassigned Slot in DefaultScheduler when Deployment is outdated
                 Key: FLINK-14859
                 URL: https://issues.apache.org/jira/browse/FLINK-14859
             Project: Flink
          Issue Type: Sub-task
          Components: Runtime / Coordination
    Affects Versions: 1.10.0
            Reporter: Gary Yao
            Assignee: Gary Yao
             Fix For: 1.10.0


In {{DefaultScheduler#assignResourceOrHandleError()}}, if the deployment is outdated, we should release the possibly acquired {{LogicalSlot}} so that we do not leak resources.

Below is an example to illustrate how slot leak is currently possible:
# Vertices A1, A2, A3 are scheduled in a batch.
# A2 acquires a slot. A1, A3 do not.
# A1 fails due to slot allocation timeout and triggers failover ({{DefaultScheduler#cancelTasksAsync}})
# A2 is canceled first and its returned slot is assigned to A3, which triggers {{DefaultScheduler#assignResourceOrHandleError}} of A3.
  However, A3 is not canceled yet but it is outdated because {{executionVertexVersioner#recordVertexModifications}} was already invoked



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