[SPARK-27709] AppStatusListener.cleanupExecutors should remove dead executors in an ordering that makes sense, not a random order

• Type: Improvement
• Status: Open
• Priority: Minor
• Resolution: Unresolved
• Affects Version/s: 3.1.0
• Component/s: Web UI
• Assignee: Unassigned
• Reporter: Josh Rosen
• Created: 14/May/19 17:29
• Updated: 16/Mar/20 22:52

Description

When AppStatusListener removes dead executors in excess of spark.ui.retainedDeadExecutors, it looks like it does so in an essentially random order:

Based on the current code it looks like we only index based on "active" but don't perform any secondary indexing or sorting based on the age / ID of the executor.

Instead, I think it might make sense to remove the oldest executors first, similar to how we order by "completionTime" when cleaning up old stages.

I think we should also consider making a higher default of spark.ui.retainedDeadExecutors: it currently defaults to 100 but this seems really low in comparison to the total number of retained tasks / stages / jobs (which collectively take much more space to store). Maybe ~1000 is a safe default?