[HADOOP-12728] "hadoop jar my.jar" should probably prioritize my.jar in the classpath by default

• Type: Improvement
• Status: Open
• Priority: Minor
• Resolution: Unresolved
• Affects Version/s: 2.7.1
• Component/s: scripts
• Hadoop Flags: Incompatible change
• Assignee: Unassigned
• Reporter: Ovidiu Gheorghioiu
• Created: 21/Jan/16 19:30
• Updated: 16/Aug/16 16:11

Description

Found this surprising behavior when testing a dev version of a jar that was already in the hadoop classpath: "hadoop jar ./my.jar" used the system my.jar, which was an old version that did not contain my bug fix. Since "hadoop jar" is the rough equivalent of running an executable, it should use the version passed on the command line.

Even worse than my case (which took a while to figure out with log messages) is when I'd be testing that the new version works the same as the old in some use case. Then I'd think it did, even though the new version was completely broken.

Allen mentioned verbally that there are some tricky aspects to this, but to open this issue for tracking / brainstorming.

Issue Links

• is related to: HADOOP-13410 RunJar adds the content of the jar twice to the classpath