[PIG-5020] Give file location for loadcaster related warning and errors

• Type: Improvement
• Status: Closed
• Priority: Minor
• Resolution: Fixed
• Fix Version/s: 0.17.0
• Hadoop Flags: Reviewed
• Assignee: Koji Noguchi
• Reporter: Koji Noguchi
• Created: 01/Sep/16 20:36
• Updated: 21/Jun/17 09:15
• Resolved: 04/Oct/16 17:27

Description

Loadcaster can be null due to bug like PIG-4974, or due to valid reasons when bytearray is returned by UDF or bytearray coming from union-ed relation with two different loadcasters.

And when casting fails at runtime, it's sometimes not straightforward to find the corresponding typecast that's failing in your script.

Caused by: org.apache.pig.backend.executionengine.ExecException: ERROR 1075: Received a bytearray from the UDF or Union from two different Loaders. Cannot determine how to convert the bytearray to string.
        at org.apache.pig.backend.hadoop.executionengine.physicalLayer.expressionOperators.POCast.getNextString(POCast.java:1122)

Maybe we can add source location when possible.