[MAPREDUCE-5034] Class cast exception in MergeManagerImpl.java

• Type: Bug
• Status: Resolved
• Priority: Major
• Resolution: Not A Problem
• Assignee: Unassigned
• Reporter: Mariappan Asokan
• Created: 26/Feb/13 23:08
• Updated: 26/Feb/13 23:37
• Resolved: 26/Feb/13 23:37

Description

When reduce side merge spills to disk, the following exception was thrown:

org.apache.hadoop.mapreduce.task.reduce.MergeManagerImpl$CompressAwarePath cannot be cast to java.lang.Comparable at java.util.TreeMap.put(TreeMap.java:542) at java.util.TreeSet.add(TreeSet.java:238) at org.apache.hadoop.mapreduce.task.reduce.MergeManagerImpl.closeOnDiskFile(MergeManagerImpl.java:340) at org.apache.hadoop.mapreduce.task.reduce.MergeManagerImpl$InMemoryMerger.merge(MergeManagerImpl.java:495) at org.apache.hadoop.mapreduce.task.reduce.MergeThread.run(MergeThread.java:94)

It looks like a bug introduced by MAPREDUCE-2264