[MAPREDUCE-5487] In task processes, JobConf is unnecessarily loaded again in Limits

• Type: Improvement
• Status: Closed
• Priority: Major
• Resolution: Fixed
• Affects Version/s: 2.1.0-beta
• Fix Version/s: 2.3.0
• Component/s: performance, task
• Hadoop Flags: Reviewed
• Assignee: Sandy Ryza
• Reporter: Sandy Ryza
• Created: 29/Aug/13 19:36
• Updated: 24/Feb/14 20:58
• Resolved: 18/Sep/13 13:59

Description

Limits statically loads a JobConf, which incurs costs of reading files from disk and parsing XML. The contents of this JobConf are identical to the one loaded by YarnChild (before adding job.xml as a resource). Allowing Limits to initialize with the JobConf loaded in YarnChild would reduce task startup time.