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https://issues.apache.org/jira/browse/HIVE-4329?page=com.atlassian.jira.plugin.system.issuetabpanels:all-tabpanel
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Carl Steinbach updated HIVE-4329:
---------------------------------
Assignee: David Chen
> HCatalog clients can't write to AvroSerde backed tables
> -------------------------------------------------------
>
> Key: HIVE-4329
> URL: https://issues.apache.org/jira/browse/HIVE-4329
> Project: Hive
> Issue Type: Bug
> Components: HCatalog, Serializers/Deserializers
> Affects Versions: 0.10.0
> Environment: discovered in Pig, but it looks like the root cause
> impacts all non-Hive users
> Reporter: Sean Busbey
> Assignee: David Chen
>
> Attempting to write to a HCatalog defined table backed by the AvroSerde fails
> with the following stacktrace:
> {code}
> java.lang.ClassCastException: org.apache.hadoop.io.NullWritable cannot be
> cast to org.apache.hadoop.io.LongWritable
> at
> org.apache.hadoop.hive.ql.io.avro.AvroContainerOutputFormat$1.write(AvroContainerOutputFormat.java:84)
> at
> org.apache.hcatalog.mapreduce.FileRecordWriterContainer.write(FileRecordWriterContainer.java:253)
> at
> org.apache.hcatalog.mapreduce.FileRecordWriterContainer.write(FileRecordWriterContainer.java:53)
> at
> org.apache.hcatalog.pig.HCatBaseStorer.putNext(HCatBaseStorer.java:242)
> at org.apache.hcatalog.pig.HCatStorer.putNext(HCatStorer.java:52)
> at
> org.apache.pig.backend.hadoop.executionengine.mapReduceLayer.PigOutputFormat$PigRecordWriter.write(PigOutputFormat.java:139)
> at
> org.apache.pig.backend.hadoop.executionengine.mapReduceLayer.PigOutputFormat$PigRecordWriter.write(PigOutputFormat.java:98)
> at
> org.apache.hadoop.mapred.MapTask$NewDirectOutputCollector.write(MapTask.java:559)
> at
> org.apache.hadoop.mapreduce.task.TaskInputOutputContextImpl.write(TaskInputOutputContextImpl.java:85)
> {code}
> The proximal cause of this failure is that the AvroContainerOutputFormat's
> signature mandates a LongWritable key and HCat's FileRecordWriterContainer
> forces a NullWritable. I'm not sure of a general fix, other than redefining
> HiveOutputFormat to mandate a WritableComparable.
> It looks like accepting WritableComparable is what's done in the other Hive
> OutputFormats, and there's no reason AvroContainerOutputFormat couldn't also
> be changed, since it's ignoring the key. That way fixing things so
> FileRecordWriterContainer can always use NullWritable could get spun into a
> different issue?
> The underlying cause for failure to write to AvroSerde tables is that
> AvroContainerOutputFormat doesn't meaningfully implement getRecordWriter, so
> fixing the above will just push the failure into the placeholder RecordWriter.
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