[
https://issues.apache.org/jira/browse/MAPREDUCE-1842?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=12875575#action_12875575
]
Age Mooij commented on MAPREDUCE-1842:
--------------------------------------
By the way, I mentioned that I thought JobId is not Serializable and that's why
I ran into this problem. As a workaround we now use the readFields and
writeFields methods to serialize our JobID instances, which is of course the
preferred way.
The forName/equals code is still broken though.
> JobID.forName() creates JobID instances that break equality
> -----------------------------------------------------------
>
> Key: MAPREDUCE-1842
> URL: https://issues.apache.org/jira/browse/MAPREDUCE-1842
> Project: Hadoop Map/Reduce
> Issue Type: Bug
> Components: job submission
> Affects Versions: 0.20.2
> Reporter: Age Mooij
>
> We have some code that uses serialization to store
> org.apache.hadoop.mapreduce.JobID instances (among other things). Since
> org.apache.hadoop.mapreduce.JobID is not serializable, we store the String
> representation and use org.apache.hadoop.mapreduce.JobID.forName(String) to
> read it back.
> Unfortunately the instance created by that method is not equal to the same id
> as created by the constructor. Here's a unit test for the problem:
> @Test
> public void forNameCopyShouldProduceInstanceEqualToOriginal() {
> JobID jobId1 = new JobID("original", 1);
> JobID jobId2 = JobID.forName(jobId1.toString());
> assertEquals(jobId1, jobId2);
> }
> forName(String) produces a backwards compatible instance from the old mapred
> package but the equals method shared by them both uses this.getClass() ==
> that.getClass() and that causes the incompatible instances.
> I know this backwards compatible stuff is important but could you please fix
> this ? The simplest fix would be to change the implementation of equals() or
> override it in the backwards compatibillity version of JobID in the old
> mapred package
--
This message is automatically generated by JIRA.
-
You can reply to this email to add a comment to the issue online.
