[SPARK-20945] Fix TID key not found in TaskSchedulerImpl

[liupc]

What changes were proposed in this pull request?

This pull request fix the TaskScheulerImpl bug in some condition.
Detail see:
https://issues.apache.org/jira/browse/SPARK-20945

(Please fill in changes proposed in this fix)

How was this patch tested?

manual tests
(Please explain how this patch was tested. E.g. unit tests, integration tests, manual tests)
(If this patch involves UI changes, please attach a screenshot; otherwise, remove this)

Please review http://spark.apache.org/contributing.html before opening a pull request.

[JoshRosen]

Hi @liupc,

Thanks for the JIRA and PR. Could you edit the PR's title to incorporate the JIRA number? e.g.

[SPARK-20945] Fix TID key not found in TaskSchedulerImpl

Also, could you re-target this PR to be against the master branch? It looks like you've opened it against branch-2.1. Our workflow for these kind of bugs is generally to open PRs against the master branch: committers will take care of backporting your fix to appropriate maintenance branches.

[srowen]

I think you lost the value of "reason" here.
It's not a big deal but you could also write:

taskIdToExecutorId.get(tid).foreach(execId => backend.killTask(tid, execId, interruptThread, reason = "stage cancelled"))

[liupc]

Looks good! I will update soon, thanks!

[SparkQA]

Test build #3775 has finished for PR 18171 at commit c4fff63.

• This patch passes all tests.
• This patch merges cleanly.
• This patch adds no public classes.

[srowen]

Merged to master

[jinxing64]

Why this is not merged into 2.2 ?