Schema change results in exception - java.lang.ClassCastException

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$ElementConverter.(AvroRecordConverter.java:536)
at org.apache.parquet.avro.AvroRecordConverter$AvroCollectionConverter.(AvroRecordConverter.java:486)
at org.apache.parquet.avro.AvroRecordConverter.newConverter(AvroRecordConverter.java:289)
at org.apache.parquet.avro.AvroRecordConverter.(AvroRecordConverter.java:141)
at org.apache.parquet.avro.AvroRecordConverter.newConverter(AvroRecordConverter.java:279)
at org.apache.parquet.avro.AvroRecordConverter.(AvroRecordConverter.java:141)
at org.apache.parquet.avro.AvroRecordConverter.(AvroRecordConverter.java:95)
at org.apache.parquet.avro.AvroRecordMaterializer.(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}]}

**Environment**: Hoodie/Parquet/Avro

Parquet-1.8.1

Avro-1.7.6
**Reporter**: [Balajee Nagasubramaniam](https://issues.apache.org/jira/secure/ViewProfile.jspa?name=balajeeUber)
**Assignee**: [Xinli Shang](https://issues.apache.org/jira/secure/ViewProfile.jspa?name=shangx@uber.com) / @shangxinli
#### Externally tracked issue: [https://issues.apache.org/jira/browse/PARQUET-1681](https://issues.apache.org/jira/browse/PARQUET-1681)

_{**Note**: *This issue was originally created as [PARQUET-1656](https://issues.apache.org/jira/browse/PARQUET-1656). Please see the [migration documentation](https://issues.apache.org/jira/browse/PARQUET-2502) for further details.*}

AvroRecordConverter と AvroReadSupport のスタックトレースのエントリポイントから始め、次に報告された変換行にある util.ParquetToAvroSchemaConverter.scala を調べます。変更前と変更後のスキーマ、およびログに記録された reader/writer スキーマを比較し、外部で追跡されている PARQUET-1681 issue を確認して、現在のステータスと definition of done を判断します。

索引モデルが issue の本文から書いたものです。