[MAPREDUCE-5814] fat jar with *-default.xml may fail when mapreduce.job.classloader=true.

• Type: Bug
• Status: Closed
• Priority: Major
• Resolution: Fixed
• Affects Version/s: 2.3.0
• Fix Version/s: 2.5.0
• Component/s: mrv2
• Target Version/s: 2.4.0
• Hadoop Flags: Reviewed
• Assignee: Gera Shegalov
• Reporter: Gera Shegalov
• Created: 27/Mar/14 12:45
• Updated: 03/Sep/14 20:33
• Resolved: 13/May/14 18:59

Description

We faced a failure when a job.jar compiled against 0.20+ hadoop artifacts had to run with mapreduce.job.classloader=true because it needed a more recent guava as a dependency. The job failed because the cluster's *-default.xml files were overshadowed by the ones in the fat jar. We propose to treat these default config files like the system packages org.apache.hadoop. to avoid a counterintuitivie behavior as if we had mapreduce.job.user.classpath.first set.

Issue Links

• is depended upon by: MAPREDUCE-5878 some standard JDK APIs are not part of system classes defaults