[HADOOP-645] Map-reduce task does not finish correctly when -reducer NONE is specified

• Type: Bug
• Status: Closed
• Priority: Major
• Resolution: Fixed
• Affects Version/s: 0.7.2
• Fix Version/s: 0.9.0
• Assignee: Dhruba Borthakur
• Reporter: Dhruba Borthakur
• Created: 26/Oct/06 20:34
• Updated: 08/Jul/09 17:05
• Resolved: 16/Nov/06 00:00

Description

Map-reduce task does not finish correctly when -reducer NONE is specified, The NONE option means that the reducer should not be generating any output. Using this option causes an exception in the task tracker:

java.lang.IllegalArgumentException: URI is not hierarchical
TaskRunner: at java.io.File.<init>(File.java:335)
TaskRunner: at org.apache.hadoop.streaming.PipeMapRed.mapRedFinished(PipeMapRed.java:583)
TaskRunner: at org.apache.hadoop.streaming.PipeMapper.close(PipeMapper.java:96)
TaskRunner: at org.apache.hadoop.mapred.MapRunner.run(MapRunner.java:49)
TaskRunner: at org.apache.hadoop.mapred.MapTask.run(MapTask.java:213)
TaskRunner: at org.apache.hadoop.mapred.TaskTracker$Child.main(TaskTracker.java:1240)
TaskRunner: sideEffectURI_ file:output length 11

Issue Links

• is related to: HADOOP-728 Map-reduce task does not produce correct results when -reducer NONE is specified through streaming