[SPARK-17176][WEB UI]set default task sort column to "Status"

[cenyuhai]

What changes were proposed in this pull request?

Task are sorted by "Index" in Stage Page, but user are always concerned about tasks which are failed(see error messages) or still running (maybe it is skewed). When there are too many tasks, it is too slow to sort. So it is better to set the default sort column to ”Status“.

[SparkQA]

Test build #64160 has finished for PR 14739 at commit c1f3c9e.

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

[srowen]

I think this has come up before and not been accepted. This happens to have the desired behavior because "FAILED" comes before "RUNNING". It doesn't sort by ID as a secondary key. It's a behavior change and most other things in Spark and elsewhere sort by ID. It's easy to sort by status.

[cenyuhai]

@srowen YES, "FAILED" will come before "RUNNING".That is what I want, because we want to know why task will fail more than the need to sort by ID, "Errors" are more import than the informations of the runnning tasks, because if there are too many failed tasks, there must be something wrong with the application.
ID is just a unique identifier for task, in the most cases, we don't care about it.But we will care about why tasks will fail, why tasks are running such a long time.
When there are too many tasks, it is not easy to sort by status, it is very slow.

[srowen]

I can see that argument, but it would be consistent with other parts of Spark and other UIs. If for some reason we had a new state that sorted before "FAILED" this wouldn't work. Users can easily sort tasks too.

[cenyuhai]

@srowen can we make it an option, default by "Index", users can choose "Status" or anything else?
Now the pagination is by jquery datatable, not by server side. When tasks are more than 10,000, It will start to become slower. If not happened in production environment, I would not have opened this PR, users advised me to sort by status.

[jiangxb1987]

@srowen should we close this?

[gatorsmile]

Really appreciate your contribution! Sorry, based on the comment, we might need to close this PR, but please submit more PRs in the future. Thanks again!