[YARN-6888] Refactor AppLevelTimelineCollector such that RM does not have aggregator threads created

• Type: Sub-task
• Status: Resolved
• Priority: Major
• Resolution: Fixed
• Fix Version/s: 2.9.0, YARN-5355, 3.0.0-beta1, YARN-5355-branch-2
• Component/s: timelineserver
• Hadoop Flags: Reviewed
• Assignee: Vrushali C
• Reporter: Vrushali C
• Created: 27/Jul/17 06:41
• Updated: 21/Oct/17 06:05
• Resolved: 28/Jul/17 06:25

Description

Currently both RM and NM use the same AppLevelTimelineCollector class. The NM requires aggregator threads per application so that it can perform in memory aggregation for application metrics but the RM does not need this. Since they share the code, RM has a bunch of "TimelineCollector Aggregation" threads created (one per running app).

Filing jira to refactor AppLevelTimelineCollector such that RM does not have aggregator threads created.