[FLINK-17478] Avro format logical type conversions do not work due to type mismatch

• Type: Sub-task
• Status: Closed
• Priority: Major
• Resolution: Duplicate
• Affects Version/s: 1.10.0
• Component/s: Formats (JSON, Avro, Parquet, ORC, SequenceFile), Table SQL / Planner
• Assignee: Unassigned
• Reporter: Gyula Fora
• Created: 30/Apr/20 10:25
• Updated: 11/May/20 09:00
• Resolved: 11/May/20 09:00

Description

We hit the following issue when trying to use avro logical timestamp types:

 

CREATE TABLE source_table (
 int_field INT,
 timestamp_field TIMESTAMP(3)
) WITH (
 'connector.type' = 'kafka',
 'connector.version' = 'universal',
 'connector.topic' = 'avro_tset',
 'connector.properties.bootstrap.servers' = '<...>',
 'format.type' = 'avro',
 'format.avro-schema' =
 '{
 "type": "record",
 "name": "test",
 "fields" : [
 {"name": "int_field", "type": "int"},
 {"name": "timestamp_field", "type": {"type":"long", "logicalType": "timestamp-millis"}}
 ]
 }'
) 
 
INSERT INTO source_table VALUES (12, TIMESTAMP '1999-11-11 11:11:11'); 

 

And the error:

Caused by: java.lang.ClassCastException: java.time.LocalDateTime cannot be cast to java.lang.Long at org.apache.avro.generic.GenericDatumWriter.writeWithoutConversion(GenericDatumWriter.java:131) at org.apache.avro.generic.GenericDatumWriter.write(GenericDatumWriter.java:72) at org.apache.avro.generic.GenericDatumWriter.writeField(GenericDatumWriter.java:166) at org.apache.avro.specific.SpecificDatumWriter.writeField(SpecificDatumWriter.java:90) at org.apache.avro.generic.GenericDatumWriter.writeRecord(GenericDatumWriter.java:156) at org.apache.avro.generic.GenericDatumWriter.writeWithoutConversion(GenericDatumWriter.java:118) at org.apache.avro.generic.GenericDatumWriter.write(GenericDatumWriter.java:75) at org.apache.avro.generic.GenericDatumWriter.write(GenericDatumWriter.java:62) at org.apache.flink.formats.avro.AvroRowSerializationSchema.serialize(AvroRowSerializationSchema.java:143)

Dawid's analysis from the ML discussion:
It seems that the information about the bridging class (java.sql.Timestamp in this case) is lost in the stack. Because this information is lost/not respected the planner produces LocalDateTime instead of a proper java.sql.Timestamp time. The AvroRowSerializationSchema expects java.sql.Timestamp for a column of TIMESTAMP type and thus it fails for LocalDateTime.