[HADOOP-17064] Drop MRv1 binary compatibility in 4.0.0

• Type: Sub-task
• Status: Open
• Priority: Major
• Resolution: Unresolved
• Labels: incompatible
• Assignee: Unassigned
• Reporter: Rungroj Maipradit
• Created: 04/Jun/20 07:04
• Updated: 06/Jun/20 19:54

Description

A code comment suggests making the setJobConf method deprecated along with mapred package HADOOP-1230. HADOOP-1230 has been closed a long time ago, but the method is still not annotated as deprecated.

 /**
   * This code is to support backward compatibility and break the compile  
   * time dependency of core on mapred.
   * This should be made deprecated along with the mapred package HADOOP-1230. 
   * Should be removed when mapred package is removed.
   */ 

Comment location: https://github.com/apache/hadoop/blob/trunk/hadoop-common-project/hadoop-common/src/main/java/org/apache/hadoop/util/ReflectionUtils.java#L88

From the previous discussion, it seems that this method is still required if we ensure binary compatibility with MRv1.
https://issues.apache.org/jira/browse/HADOOP-17047?focusedCommentId=17111702&page=com.atlassian.jira.plugin.system.issuetabpanels%3Acomment-tabpanel#comment-17111702

Mingliang Liu suggested to Drop MRv1 binary compatibility in 4.0.0
https://issues.apache.org/jira/browse/HADOOP-17047?focusedCommentId=17112442&page=com.atlassian.jira.plugin.system.issuetabpanels%3Acomment-tabpanel#comment-17112442