[SPARK-10851][SPARKR] Exception not failing R applications (in yarn cluster mode)

[sun-rui]

The YARN backend doesn't like when user code calls System.exit, since it cannot know the exit status and thus cannot set an appropriate final status for the application.

This PR remove the usage of system.exit to exit the RRunner. Instead, when the R process running an SparkR script returns an exit code other than 0, throws SparkUserAppException which will be caught by ApplicationMaster and ApplicationMaster knows it failed. For other failures, throws SparkException.

[shivaram]

Thanks @sun-rui for the PR. I didn't follow the problem report very closely -- Could you explain the fix in the PR description for it to be available in the future ?

[SparkQA]

Test build #43077 has finished for PR 8938 at commit b296066.

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

[shivaram]

cc @andrewor14

[shivaram]

Thanks @sun-rui -- LGTM. I'll just give this some time to see if @andrewor14 has any comments.

[felixcheung]

looks good

[andrewor14]

OK, merging into master, thanks.