[MAPREDUCE-6070] yarn.app.am.resource.mb/cpu-vcores affects uber mode but is not documented

• Type: Improvement
• Status: Closed
• Priority: Trivial
• Resolution: Fixed
• Affects Version/s: 2.4.0, 2.5.0
• Fix Version/s: 2.6.0
• Component/s: documentation
• Hadoop Flags: Reviewed
• Assignee: Tsuyoshi Ozawa
• Reporter: Tsuyoshi Ozawa
• Created: 20/May/14 07:39
• Updated: 01/Dec/14 03:09
• Resolved: 11/Sep/14 16:23

Description

We should document the condition when uber mode is enabled. Currently, users need to read following code to understand the condition.

    boolean smallMemory =
        ( (Math.max(conf.getLong(MRJobConfig.MAP_MEMORY_MB, 0),
            conf.getLong(MRJobConfig.REDUCE_MEMORY_MB, 0))
            <= sysMemSizeForUberSlot)
            || (sysMemSizeForUberSlot == JobConf.DISABLED_MEMORY_LIMIT));
   boolean smallCpu =
            Math.max(
                conf.getInt(
                    MRJobConfig.MAP_CPU_VCORES, 
                    MRJobConfig.DEFAULT_MAP_CPU_VCORES), 
                conf.getInt(
                    MRJobConfig.REDUCE_CPU_VCORES, 
                    MRJobConfig.DEFAULT_REDUCE_CPU_VCORES)) 
             <= sysCPUSizeForUberSlot