Avro's isElementType() change breaks the reading of some parquet(1.8.1) files
- Lenguaje dominante
- Java
- Estrellas
- 3.1k
- Forks
- 1.6k
- Merge medio
- 3 d 12 h
- PR fusionados (30 d)
- 33
Descripción
When using the Avro schema below to write a parquet(1.8.1) file and then read back by using parquet 1.10.1 without passing any schema, the reading throws an exception "XXX is not a group" . Reading through parquet 1.8.1 is fine.
{
"name": "phones",
"type": [
"null",
{
"type": "array",
"items": {
"type": "record",
"name": "phones_items",
"fields": [
{ "name": "phone_number", "type": [ "null", "string" ], "default": null }
]
}
}
],
"default": null
}
The code to read is as below
val reader = AvroParquetReader._builder_[SomeRecordType](parquetPath).withConf(**new** Configuration).build()
reader.read()
PARQUET-651 changed the method isElementType() by relying on Avro's checkReaderWriterCompatibility() to check the compatibility. However, checkReaderWriterCompatibility() consider the ParquetSchema and the AvroSchema(converted from File schema) as not compatible(the name in avro schema is ‘phones_items’, but the name is ‘array’ in Parquet schema, hence not compatible) . Hence return false and caused the “phone_number” field in the above schema to be considered as group type which is not true. Then the exception throws as .asGroupType().
I didn’t try writing via parquet 1.10.1 would reproduce the same problem or not. But it could because the translation of Avro schema to Parquet schema is not changed(didn’t verify yet).
I hesitate to revert PARQUET-651 because it solved several problems. I would like to hear the community's thoughts on it.
**Reporter**: [Xinli Shang](https://issues.apache.org/jira/secure/ViewProfile.jspa?name=shangx@uber.com) / @shangxinli
**Assignee**: [Xinli Shang](https://issues.apache.org/jira/secure/ViewProfile.jspa?name=shangx@uber.com) / @shangxinli
#### Related issues:
- [Parquet-avro fails to decode array of record with a single field name "element" correctly](https://github.com/apache/parquet-java/issues/1976) (causes)
**Note**: *This issue was originally created as [PARQUET-1681](https://issues.apache.org/jira/browse/PARQUET-1681). Please see the [migration documentation](https://issues.apache.org/jira/browse/PARQUET-2502) for further details.*
Guía de contribución
No hay ninguna guía de contribución indexada para este repositorio
Línea de trabajo
Reproduce el fallo con el esquema Avro proporcionado, la salida de parquet 1.8.1, parquet 1.10.1 y AvroParquetReader; después, inspecciona la lógica de isElementType() modificada por PARQUET-651 y su comprobación de compatibilidad. Se considera terminado cuando los archivos antiguos con este esquema de matriz de registros se puedan leer sin la excepción “not a group”, y el comportamiento esté cubierto por una prueba de regresión si el repositorio proporciona una.
Escrito por el modelo de indexación a partir del texto del issue.
Evaluación
- Stack tecnológico
- java
- Área
- data-engineering
- Tipo de issue
- Error
- Dificultad
- 4/5
- Tiempo estimado
- 3-5 días
- Estado de actividad
- Estancado
- Claridad
- Bastante claro
- Aptitud para principiantes
- 35/100