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https://issues.apache.org/jira/browse/GORA-346?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=14161669#comment-14161669
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Ivan Zolotov commented on GORA-346:
-----------------------------------

As I understood, gora shim layer allows to instantiate appropriate Job and 
JobContext classes for the certain hadoop version. It works very well. But what 
about TaskAttemptContext?
I've just tried to run nutch2 on hadoop2 and the following stack trace has been 
shown:
java.lang.IncompatibleClassChangeError: Found interface 
org.apache.hadoop.mapreduce.TaskAttemptContext, but class was expected at 
org.apache.gora.mapreduce.GoraOutputFormat.getRecordWriter(GoraOutputFormat.java:83)
 at 
org.apache.hadoop.mapred.MapTask$NewDirectOutputCollector.<init>(MapTask.java:624)
 at org.apache.hadoop.mapred.MapTask.runNewMapper(MapTask.java:744) at 
org.apache.hadoop.mapred.MapTask.run(MapTask.java:340) at 
org.apache.hadoop.mapred.LocalJobRunner$Job$MapTaskRunnable.run(LocalJobRunner.java:243)
 at java.util.concurrent.Executors$RunnableAdapter.call(Executors.java:471) at 
java.util.concurrent.FutureTask.run(FutureTask.java:262) at 
java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1145) 
at 
java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:615) 
at java.lang.Thread.run(Thread.java:745)
Gora-core module has explicit dependency from hadoop-core where 
TaskAttemptContext is class, but in hadoop2 TaskAttemptContext is an interface. 
So, to I have to replace gora-core dependency to make gora-core compatible with 
hadoop2. Because of it, it seems like gora-0.5 isn't compatible with hadoop2 
out of the box.
Please, correct me if I'm wrong.
Thanks.

> Create shim layer to support multiple hadoop versions
> -----------------------------------------------------
>
>                 Key: GORA-346
>                 URL: https://issues.apache.org/jira/browse/GORA-346
>             Project: Apache Gora
>          Issue Type: Improvement
>    Affects Versions: 0.5
>            Reporter: Renato Javier MarroquĂ­n Mogrovejo
>            Assignee: Moritz Hoffmann
>              Labels: patch
>             Fix For: 0.5
>
>         Attachments: GORA-345_MUNGE_v1.patch, GORA-346_v1.patch, 
> GORA-346_v2.patch, GORA-346_v3.patch, GORA-346_v4_profiles.patch, 
> GORA-346_v5.patch
>
>




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