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Posted to user@avro.apache.org by nir_zamir <ni...@gmail.com> on 2013/03/24 11:23:08 UTC
Union in AvroMapper.map: Not in Union??
Hi,
I have a small M/R which, for the sake of troubleshooting, just reads a
single Avro file and sends it to an AvroMapper. In order to handle different
schemas, I set the mapper to work with a Union Schema.
For the simplicity, the union is a union of only one schema, taken from the
Avro file. This is my run function:
public int run2(String[] args) throws Exception {
List<Schema> schemas= new ArrayList<Schema>();
Schema schema = readSchema(new Path(inputDir), conf);
schemas.add(schema);
Schema unionSchema = Schema.createUnion(schemas);
AvroJob.setInputSchema(conf, unionSchema);
AvroJob.setMapOutputSchema(conf,
Pair.getPairSchema(Schema.create(Type.INT),
unionSchema));
JobClient.runJob(conf);
return 0;
}
And my mapper is:
public static class MyMap extends AvroMapper <GenericRecord,
Pair<Integer, GenericRecord>> {
@Override
public void map( GenericRecord datum, AvroCollector<Pair<Integer,
GenericRecord>> collector, Reporter reporter) throws IOException {
collector.collect(new Pair<Integer, GenericRecord>(conversion_id,
datum));
}
}
*Side note:* when I extract the schema manually from the Avro file and call
GenericData.get().resolveUnion - the schema is correctly resolved and found
in the union schema (the methods returns 0).
*THE PROBLEM:*
the 'collect' method throws an exception saying my datum's schema is not in
the union:
org.apache.avro.UnresolvedUnionException: Not in union
[{"type":"record","name":"path_to_conversions_raw","namespace":"org.apache.avro.mapred","doc":"Sqoop
import of
path_to_conversions_raw","fields":[{"name":"conversion_id","type":["long","null"],"columnName":"conversion_id","sqlType":"-5"},{"name":"conversion_time","type":["long","null"],"columnName":"conversion_time","sqlType":"93"},{"name":"derived_time","type":["long","null"],"columnName":"derived_time","sqlType":"93"},{"name":"position","type":["int","null"],"columnName":"position","sqlType":"5"},{"name":"event_time","type":["long","null"],"columnName":"event_time","sqlType":"93"},{"name":"event_type_id","type":["int","null"],"columnName":"event_type_id","sqlType":"5"},{"name":"entity_id","type":["int","null"],"columnName":"entity_id","sqlType":"4"},{"name":"entity_type_id","type":["int","null"],"columnName":"entity_type_id","sqlType":"4"},{"name":"sv_click_type","type":["int","null"],"columnName":"sv_click_type","sqlType":"5"},{"name":"placement_id","type":["int","null"],"columnName":"placement_id","sqlType":"4"},{"name":"site_id","type":["int","null"],"columnName":"site_id","sqlType":"4"},{"name":"campaign_id","type":["int","null"],"columnName":"campaign_id","sqlType":"4"},{"name":"days_before_conversion","type":["int","null"],"columnName":"days_before_conversion","sqlType":"5"},{"name":"version_id","type":["int","null"],"columnName":"version_id","sqlType":"4"},{"name":"target_audience_id","type":["int","null"],"columnName":"target_audience_id","sqlType":"4"},{"name":"ip_attributes_id","type":["long","null"],"columnName":"ip_attributes_id","sqlType":"-5"},{"name":"batch_id","type":["long","null"],"columnName":"batch_id","sqlType":"-5"},{"name":"ccs_ad_id","type":["long","null"],"columnName":"ccs_ad_id","sqlType":"-5"}],"tableName":"path_to_conversions_raw"}]:
{"conversion_id": 552804, "conversion_time": 1325451223000, "derived_time":
1330639180000, "position": 2, "event_time": 1325401200000, "event_type_id":
1, "entity_id": 4035315, "entity_type_id": 1, "sv_click_type": 2,
"placement_id": 1978266, "site_id": 9103, "campaign_id": 129001,
"days_before_conversion": 1, "version_id": 73721, "target_audience_id": -1,
"ip_attributes_id": 3598, "batch_id": 4601, "ccs_ad_id": null}
at org.apache.avro.generic.GenericData.resolveUnion(GenericData.java:542)
at
org.apache.avro.generic.GenericDatumWriter.resolveUnion(GenericDatumWriter.java:137)
at
org.apache.avro.generic.GenericDatumWriter.write(GenericDatumWriter.java:70)
at
org.apache.avro.reflect.ReflectDatumWriter.write(ReflectDatumWriter.java:104)
at
org.apache.avro.generic.GenericDatumWriter.write(GenericDatumWriter.java:57)
at
org.apache.avro.mapred.AvroSerialization$AvroWrapperSerializer.serialize(AvroSerialization.java:127)
at
org.apache.avro.mapred.AvroSerialization$AvroWrapperSerializer.serialize(AvroSerialization.java:110)
at
org.apache.hadoop.mapred.MapTask$MapOutputBuffer.collect(MapTask.java:916)
at
org.apache.hadoop.mapred.MapTask$OldOutputCollector.collect(MapTask.java:501)
at
org.apache.avro.mapred.HadoopMapper$MapCollector.collect(HadoopMapper.java:69)
at example.avro.ColorCount$MyMap.map(ColorCount.java:51)
Any help would be appreciated..
Thanks!
Nir
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Re: Union in AvroMapper.map: Not in Union??
Posted by nir_zamir <ni...@gmail.com>.
Hi Martin,
Thanks.
According to this, using the union should work:
http://apache-avro.679487.n3.nabble.com/Multiple-input-schemas-in-MapReduce-td2928590.html
BTW, I had a chance to debug the failing code, and the reason for it is
described in a different thread I posted:
http://apache-avro.679487.n3.nabble.com/Parsing-a-Pair-s-value-inherited-namespace-td4026810.html
Thanks,
Nir
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Re: Union in AvroMapper.map: Not in Union??
Posted by Martin Kleppmann <ma...@rapportive.com>.
On 10 April 2013 11:47, Doug Cutting <cu...@apache.org> wrote:
> On Tue, Apr 9, 2013 at 8:55 PM, Martin Kleppmann <ma...@rapportive.com>wrote:
>
>> AvroJob does not perform schema evolution, so the schema you provide
>> to AvroJob.setInputSchema has to be the exact same schema with which
>> your input files to the mappers are encoded.
>>
>
> Actually the schema you provide is used as the "reader" schema and need
> not exactly match the schema used to write the data. The schema used when
> writing is stored in the data files.
>
Oh yes — sorry, I misread the code. (I overlooked the fact that
DataFileStream.initialize mutates the reader to use the writer's schema.)
Martin
Re: Union in AvroMapper.map: Not in Union??
Posted by Doug Cutting <cu...@apache.org>.
On Tue, Apr 9, 2013 at 8:55 PM, Martin Kleppmann <ma...@rapportive.com>wrote:
> AvroJob does not perform schema evolution, so the schema you provide
> to AvroJob.setInputSchema has to be the exact same schema with which
> your input files to the mappers are encoded.
>
Actually the schema you provide is used as the "reader" schema and need not
exactly match the schema used to write the data. The schema used when
writing is stored in the data files.
Doug
Re: Union in AvroMapper.map: Not in Union??
Posted by Martin Kleppmann <ma...@rapportive.com>.
Hi Nir,
I'm not an expert with the avro.mapred APIs, but as far as I know,
AvroJob does not perform schema evolution, so the schema you provide
to AvroJob.setInputSchema has to be the exact same schema with which
your input files to the mappers are encoded. So if your input isn't
actually a union type, but your schema says that it is, decoding of
the input file will fail.
If you want to consume several different input directories with
different schemas in the same MapReduce job, you might be able to
build that using Hadoop's MultipleInputs, though I don't know how well
that plays with Avro. Alternatively, you could take a look at
http://crunch.apache.org/ which provides higher-level MapReduce APIs
and is designed to play nicely with Avro.
Hope that helps,
Martin
On 24 March 2013 03:23, nir_zamir <ni...@gmail.com> wrote:
> Hi,
>
> I have a small M/R which, for the sake of troubleshooting, just reads a
> single Avro file and sends it to an AvroMapper. In order to handle different
> schemas, I set the mapper to work with a Union Schema.
> For the simplicity, the union is a union of only one schema, taken from the
> Avro file. This is my run function:
>
> public int run2(String[] args) throws Exception {
> List<Schema> schemas= new ArrayList<Schema>();
> Schema schema = readSchema(new Path(inputDir), conf);
> schemas.add(schema);
> Schema unionSchema = Schema.createUnion(schemas);
>
> AvroJob.setInputSchema(conf, unionSchema);
> AvroJob.setMapOutputSchema(conf,
> Pair.getPairSchema(Schema.create(Type.INT),
> unionSchema));
>
> JobClient.runJob(conf);
> return 0;
> }
>
> And my mapper is:
>
> public static class MyMap extends AvroMapper <GenericRecord,
> Pair<Integer, GenericRecord>> {
> @Override
> public void map( GenericRecord datum, AvroCollector<Pair<Integer,
> GenericRecord>> collector, Reporter reporter) throws IOException {
> collector.collect(new Pair<Integer, GenericRecord>(conversion_id,
> datum));
> }
> }
>
> *Side note:* when I extract the schema manually from the Avro file and call
> GenericData.get().resolveUnion - the schema is correctly resolved and found
> in the union schema (the methods returns 0).
>
>
> *THE PROBLEM:*
> the 'collect' method throws an exception saying my datum's schema is not in
> the union:
>
> org.apache.avro.UnresolvedUnionException: Not in union
> [{"type":"record","name":"path_to_conversions_raw","namespace":"org.apache.avro.mapred","doc":"Sqoop
> import of
> path_to_conversions_raw","fields":[{"name":"conversion_id","type":["long","null"],"columnName":"conversion_id","sqlType":"-5"},{"name":"conversion_time","type":["long","null"],"columnName":"conversion_time","sqlType":"93"},{"name":"derived_time","type":["long","null"],"columnName":"derived_time","sqlType":"93"},{"name":"position","type":["int","null"],"columnName":"position","sqlType":"5"},{"name":"event_time","type":["long","null"],"columnName":"event_time","sqlType":"93"},{"name":"event_type_id","type":["int","null"],"columnName":"event_type_id","sqlType":"5"},{"name":"entity_id","type":["int","null"],"columnName":"entity_id","sqlType":"4"},{"name":"entity_type_id","type":["int","null"],"columnName":"entity_type_id","sqlType":"4"},{"name":"sv_click_type","type":["int","null"],"columnName":"sv_click_type","sqlType":"5"},{"name":"placement_id","type":["int","null"],"columnName":"placement_id","sqlType":"4"},{"name":"site_id","type":["int","null"],"columnName":"site_id","sqlType":"4"},{"name":"campaign_id","type":["int","null"],"columnName":"campaign_id","sqlType":"4"},{"name":"days_before_conversion","type":["int","null"],"columnName":"days_before_conversion","sqlType":"5"},{"name":"version_id","type":["int","null"],"columnName":"version_id","sqlType":"4"},{"name":"target_audience_id","type":["int","null"],"columnName":"target_audience_id","sqlType":"4"},{"name":"ip_attributes_id","type":["long","null"],"columnName":"ip_attributes_id","sqlType":"-5"},{"name":"batch_id","type":["long","null"],"columnName":"batch_id","sqlType":"-5"},{"name":"ccs_ad_id","type":["long","null"],"columnName":"ccs_ad_id","sqlType":"-5"}],"tableName":"path_to_conversions_raw"}]:
> {"conversion_id": 552804, "conversion_time": 1325451223000, "derived_time":
> 1330639180000, "position": 2, "event_time": 1325401200000, "event_type_id":
> 1, "entity_id": 4035315, "entity_type_id": 1, "sv_click_type": 2,
> "placement_id": 1978266, "site_id": 9103, "campaign_id": 129001,
> "days_before_conversion": 1, "version_id": 73721, "target_audience_id": -1,
> "ip_attributes_id": 3598, "batch_id": 4601, "ccs_ad_id": null}
> at org.apache.avro.generic.GenericData.resolveUnion(GenericData.java:542)
> at
> org.apache.avro.generic.GenericDatumWriter.resolveUnion(GenericDatumWriter.java:137)
> at
> org.apache.avro.generic.GenericDatumWriter.write(GenericDatumWriter.java:70)
> at
> org.apache.avro.reflect.ReflectDatumWriter.write(ReflectDatumWriter.java:104)
> at
> org.apache.avro.generic.GenericDatumWriter.write(GenericDatumWriter.java:57)
> at
> org.apache.avro.mapred.AvroSerialization$AvroWrapperSerializer.serialize(AvroSerialization.java:127)
> at
> org.apache.avro.mapred.AvroSerialization$AvroWrapperSerializer.serialize(AvroSerialization.java:110)
> at
> org.apache.hadoop.mapred.MapTask$MapOutputBuffer.collect(MapTask.java:916)
> at
> org.apache.hadoop.mapred.MapTask$OldOutputCollector.collect(MapTask.java:501)
> at
> org.apache.avro.mapred.HadoopMapper$MapCollector.collect(HadoopMapper.java:69)
> at example.avro.ColorCount$MyMap.map(ColorCount.java:51)
>
>
> Any help would be appreciated..
>
> Thanks!
> Nir
>
>
>
>
>
> --
> View this message in context: http://apache-avro.679487.n3.nabble.com/Union-in-AvroMapper-map-Not-in-Union-tp4026706.html
> Sent from the Avro - Users mailing list archive at Nabble.com.
Re: Union in AvroMapper.map: Not in Union??
Posted by nir_zamir <ni...@gmail.com>.
Hi,
Update:
The issue was resolved by a patch of Avro, posted by Doug.
Thread:
http://apache-avro.679487.n3.nabble.com/Parsing-a-Pair-s-value-inherited-namespace-td4026810.html
Issue: https://issues.apache.org/jira/browse/AVRO-1295
Thanks,
Nir
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Re: Union in AvroMapper.map: Not in Union??
Posted by nir_zamir <ni...@gmail.com>.
Help please...
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