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Avro, mail # user - Error using Avro 1.7.4 Specific API with .mapreduce

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Error using Avro 1.7.4 Specific API with .mapreduce
Ramachandran, Karthik 2013-03-01, 02:58

I'm trying to write a Mapper (using the .mapreduce) api that takes an Avro 1.7.4 file. I'm using the specific API (the maven avro plugin) to generate my objects from an
.avdl file.

I've verified that the Avro file is generated correctly and can use the avro-to-json function in the Avro tools jar to read the file back.

The error I'm receiving is :

java.lang.ClassCastException: org.apache.avro.generic.GenericData$Record cannot be cast to org.lab41.cyprus.domain.NetworkRecord
    at org.lab41.cyprus.mapreduce.RollupAvroFilesMapper.map(RollupAvroFilesMapper.java:45)
    at org.lab41.cyprus.mapreduce.RollupAvroFilesMapper.map(RollupAvroFilesMapper.java:23)
    at org.apache.hadoop.mapreduce.Mapper.run(Mapper.java:140)
    at org.apache.hadoop.mapred.MapTask.runNewMapper(MapTask.java:645)
    at org.apache.hadoop.mapred.MapTask.run(MapTask.java:325)
    at org.apache.hadoop.mapred.LocalJobRunner$Job.run(LocalJobRunner.java:263)\
The driver class is as follows :

public class RollupAvroFiles extends Configured implements Tool{

    public int run(String[] args) throws Exception {
        Configuration conf = getConf();
        String[] otherArgs = new GenericOptionsParser(conf, args).getRemainingArgs();

        String input, output;
        if (otherArgs.length == 2) {
            input = otherArgs[0];
            output = otherArgs[1];
        } else {
            return 1;

        /** configure Job **/
        Job job = new Job(conf, "RollupAvroFiles");

        FileInputFormat.setInputPaths(job, new Path(input));
        AvroJob.setInputKeySchema(job, NetworkRecord.SCHEMA$);
        AvroJob.setMapOutputKeySchema(job, Schema.create(Schema.Type.LONG));
        AvroJob.setMapOutputValueSchema(job, NetworkRecord.SCHEMA$);


        AvroJob.setOutputKeySchema(job, NetworkRecord.SCHEMA$);

        FileOutputFormat.setOutputPath(job, new Path(output));

        return job.waitForCompletion(true) ? 0 : 1;

    public static void main(String[] args) throws Exception {
        int exitCode = ToolRunner.run(new RollupAvroFiles(), args);


And the Mapper class reads :

public class RollupAvroFilesMapper
        extends Mapper<AvroKey<NetworkRecord>, NullWritable, AvroKey<Long>, AvroValue<NetworkRecord>> {

    protected void setup(Context context) throws IOException, InterruptedException {

    protected void map(AvroKey<NetworkRecord> key, NullWritable value, Context context)
            throws IOException, InterruptedException {
NetworkRecord = key.datum();

Any thoughts would be appreicated
Karthik Ramachandran
Software Developer, Lab41
Mobile: (571) 455-5576

Erick Tryzelaar 2013-03-01, 17:52