[MAPREDUCE-6696] Add a configuration to limit the number of map tasks allowed per job.

• Type: Improvement
• Status: Resolved
• Priority: Major
• Resolution: Fixed
• Affects Version/s: 2.8.0
• Fix Version/s: 2.9.0, 3.0.0-alpha1
• Component/s: job submission
• Target Version/s: 2.9.0
• Hadoop Flags: Reviewed
• Assignee: Zhihai Xu
• Reporter: Zhihai Xu
• Created: 16/May/16 07:47
• Updated: 30/Aug/16 01:13
• Resolved: 20/May/16 02:26

Description

Add a configuration "mapreduce.job.max.map" to limit the number of map tasks allowed per job. It will be useful for Hadoop admin to save Hadoop cluster resource by preventing users from submitting big mapreduce jobs. A mapredeuce job with too many mappers may fail with OOM after running for long time. It will be a big waste.