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Avro, mail # user - Avro and Oozie Map Reduce action


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Re: Avro and Oozie Map Reduce action
Harsh J 2013-03-19, 05:26
The value you're specifying for io.serializations below is incorrect:

<property>
<name>io.serializations</name>
<value>org.apache.avro.mapred.AvroSerialization,
avro.serialization.key.reader.schema,
avro.serialization.value.reader.schema,
avro.serialization.key.writer.schema,avro.serialization.value.writer.schema
</value>
</property>

If the goal is to include org.apache.avro.mapred.AvroSerialization,
then it should look more like:

<property>
  <name>io.serializations</name>
  <value>org.apache.hadoop.io.serializer.WritableSerialization,org.apache.hadoop.io.serializer.avro.AvroSpecificSerialization,org.apache.hadoop.io.serializer.avro.AvroReflectSerialization,org.apache.avro.mapred.AvroSerialization</value>
</property>

That is, it must be an extension of the default values, and not a
replacement of them.

On Wed, Mar 13, 2013 at 4:05 AM, M, Paul <[EMAIL PROTECTED]> wrote:
> Hello,
>
> I am trying to run an M/R job with Avro serialization via Oozie.  I've made
> some progress in the workflow.xml, however I am still running into the
> following error.  Any thoughts?  I believe it may have to do with the
> io.serializations property below.   FYI, I am using CDH 4.2.0 mr1.
>
> 2013-03-12 15:24:32,334 INFO org.apache.hadoop.mapred.TaskInProgress: Error
> from attempt_201303111118_0080_m_000000_3: java.lang.NullPointerException
> at org.apache.hadoop.mapred.MapTask.getSplitDetails(MapTask.java:356)
> at org.apache.hadoop.mapred.MapTask.runOldMapper(MapTask.java:389)
> at org.apache.hadoop.mapred.MapTask.run(MapTask.java:333)
> at org.apache.hadoop.mapred.Child$4.run(Child.java:268)
> at java.security.AccessController.doPrivileged(Native Method)
> at javax.security.auth.Subject.doAs(Subject.java:396)
> at
> org.apache.hadoop.security.UserGroupInformation.doAs(UserGroupInformation.java:1407)
> at org.apache.hadoop.mapred.Child.main(Child.java:262)
>
>
> <action name="mr-node">
> <map-reduce>
> <job-tracker>${jobTracker}</job-tracker>
> <name-node>${nameNode}</name-node>
> <prepare>
> <delete path="${nameNode}/user/${wf:user()}/${outputDir}" />
> </prepare>
> <configuration>
> <property>
> <name>mapred.job.queue.name</name>
> <value>${queueName}</value>
> </property>
>
> <property>
> <name>mapreduce.reduce.class</name>
> <value>org.apache.avro.mapred.HadoopReducer</value>
> </property>
> <property>
> <name>mapreduce.map.class</name>
> <value>org.apache.avro.mapred.HadoopMapper</value>
> </property>
>
>
> <property>
> <name>avro.reducer</name>
> <value>org.my.project.mapreduce.CombineAvroRecordsByHourReducer
> </value>
> </property>
>
> <property>
> <name>avro.mapper</name>
> <value>org.my.project.mapreduce.ParseMetadataAsTextIntoAvroMapper
> </value>
> </property>
>
>
> <property>
> <name>mapreduce.inputformat.class</name>
> <value>org.my.project.mapreduce.NonSplitableInputFormat</value>
> </property>
>
> <!-- Key Value Mapper -->
> <property>
> <name>avro.output.schema</name>
> <value>{"type":"record","name":"Pair","namespace":"org.apache.avro.mapred","fields":..."}]}
> </value>
> </property>
> <property>
> <name>mapred.mapoutput.key.class</name>
> <value>org.apache.avro.mapred.AvroKey</value>
> </property>
> <property>
> <name>mapred.mapoutput.value.class</name>
> <value>org.apache.avro.mapred.AvroValue</value>
> </property>
>
>
> <property>
> <name>avro.schema.output.key</name>
> <value>{"type":"record","name":"DataRecord","namespace":...]}]}
> </value>
> </property>
>
> <property>
> <name>mapreduce.outputformat.class</name>
> <value>org.apache.hadoop.mapreduce.lib.output.TextOutputFormat
> </value>
> </property>
>
> <property>
> <name>mapred.output.key.comparator.class</name>
> <value>org.apache.avro.mapred.AvroKeyComparator</value>
> </property>
>
> <property>
> <name>io.serializations</name>
> <value>org.apache.avro.mapred.AvroSerialization,
> avro.serialization.key.reader.schema,
> avro.serialization.value.reader.schema,
> avro.serialization.key.writer.schema,avro.serialization.value.writer.schema
> </value>
> </property>
>
> <property>

Harsh J