[PARQUET-1656] Schema change results in exception - java.lang.ClassCastException

• Type: Bug
• Status: Open
• Priority: Major
• Resolution: Unresolved
• Affects Version/s: 1.8.1, 1.12.0
• Component/s: parquet-avro
• Labels: Parquet avro

Environment

Hoodie/Parquet/Avro

Parquet-1.8.1

Avro-1.7.6

• External issue URL: https://issues.apache.org/jira/browse/PARQUET-1681
• External issue ID: PARQUET-1681
• Assignee: Xinli Shang
• Reporter: Balajee Nagasubramaniam
• Created: 18/Sep/19 18:14
• Updated: 21/Dec/19 00:53

Description

Following exception was seen with parquet 1.8.1 (and in parquet 1.12.0, when trying to reproduce it).

Exception in thread "main" java.lang.ClassCastException: optional binary phone_number (STRING) is not a group
at com.uber.komondor.shaded.org.apache.parquet.schema.Type.asGroupType(Type.java:250)
at com.uber.komondor.shaded.org.apache.parquet.avro.AvroRecordConverter.newConverter(AvroRecordConverter.java:279)
at com.uber.komondor.shaded.org.apache.parquet.avro.AvroRecordConverter.newConverter(AvroRecordConverter.java:232)
at com.uber.komondor.shaded.org.apache.parquet.avro.AvroRecordConverter.access$100(AvroRecordConverter.java:78)
at org.apache.parquet.avro.AvroRecordConverter$AvroCollectionConverter$ElementConverter.<init>(AvroRecordConverter.java:536)
at org.apache.parquet.avro.AvroRecordConverter$AvroCollectionConverter.<init>(AvroRecordConverter.java:486)
at org.apache.parquet.avro.AvroRecordConverter.newConverter(AvroRecordConverter.java:289)
at org.apache.parquet.avro.AvroRecordConverter.<init>(AvroRecordConverter.java:141)
at org.apache.parquet.avro.AvroRecordConverter.newConverter(AvroRecordConverter.java:279)
at org.apache.parquet.avro.AvroRecordConverter.<init>(AvroRecordConverter.java:141)
at org.apache.parquet.avro.AvroRecordConverter.<init>(AvroRecordConverter.java:95)
at org.apache.parquet.avro.AvroRecordMaterializer.<init>(AvroRecordMaterializer.java:33)
at org.apache.parquet.avro.AvroReadSupport.prepareForRead(AvroReadSupport.java:138)
at org.apache.parquet.hadoop.InternalParquetRecordReader.initialize(InternalParquetRecordReader.java:183)
at org.apache.parquet.hadoop.ParquetReader.initReader(ParquetReader.java:156)
at org.apache.parquet.hadoop.ParquetReader.read(ParquetReader.java:135)
at util.ParquetToAvroSchemaConverter$.convert(ParquetToAvroSchemaConverter.scala:46)
at util.ParquetToAvroSchemaConverter$.main(ParquetToAvroSchemaConverter.scala:20)
at util.ParquetToAvroSchemaConverter.main(ParquetToAvroSchemaConverter.scala)
at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:62)
at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
at java.lang.reflect.Method.invoke(Method.java:498)
at org.apache.hadoop.util.RunJar.run(RunJar.java:221)
at org.apache.hadoop.util.RunJar.main(RunJar.java:136)

Original exception was triggered by the following schema change.
Schema Before change:
{
"default": null,
"name": "master_cluster",
"type": [
"null",
{
"fields": [

{ "name": "uuid", "type": "string" }

,

{ "name": "namespace", "type": "string" }

,

{ "name": "version", "type": "long" }

],
"name": "master_cluster",
"type": "record"
}
]
},

After schema change:
{
"default": null,
"name": "master_cluster",
"type": [
"null",
{
"fields": [

{ "default": null, "name": "uuid", "type": [ "null", "string" ] }

,

{ "default": null, "name": "namespace", "type": [ "null", "string" ] }

,

{ "default": null, "name": "version", "type": [ "null", "long" ] }

],
"name": "VORGmaster_cluster",
"type": "record"
}
]
},

We were suspecting PARQUET-1441 could be in play and tried to reproduce the issue on parquet-1.12.0 and seeing the same exception.

During the repro noticed that issue could be with avroSchema conversion (field name was substituted with generic name "array"). While we look into this further, want to get community input on whether this is a known issue and any thoughts on path forward.

19/09/12 22:34:37 DEBUG avro.SchemaCompatibility: Checking compatibility of reader {"type":"record","name":"IDphones_items","fields":[

{"name":"phone_number","type":["null","string"],"default":null}

]} with writer {"type":"record","name":"array","fields":[

{"name":"phone_number","type":["null","string"],"default":null}

]}