[SPARK-3540] Add reboot-slaves functionality to the ec2 script

[rxin]

Tested on a real cluster.

[SparkQA]

QA tests have started for PR 2404 at commit 00a2dbd.

• This patch merges cleanly.

[SparkQA]

QA tests have finished for PR 2404 at commit 00a2dbd.

• This patch passes unit tests.
• This patch merges cleanly.
• This patch adds the following public classes (experimental):
  • class ArrayConstructor extends net.razorvine.pickle.objects.ArrayConstructor

[shivaram]

LGTM

[rxin]

@ScrapCodes any idea why random public classes are being reported, even though they have nothing to do with this PR?

[rxin]

Merging in master. Thanks.

[ScrapCodes]

It happens because in the git diff the script compares the PR branch with master and if PR is not rebased to the tip of master. False reporting will happen.

[ScrapCodes]

So I guess it came from the commit, da33acb. But this seems to be present in your branch. So may be I will have to dig deeper.

[nchammas]

It happens because in the git diff the script compares the PR branch with master and if PR is not rebased to the tip of master. False reporting will happen.

Won't those changes show up as removed lines though? The script that posts these new classes filters in only added lines.

[nchammas]

Actually, I guess if a class was removed from master but not also removed from the PR fork, then that would show up as an added class.