[AVRO-1661] Schema Evolution not working

• Type: Improvement
• Status: Resolved
• Priority: Major
• Resolution: Invalid
• Affects Version/s: 1.7.6, 1.7.7
• Component/s: java
• Labels: avsc evolution schema

Environment

Ubuntu 14.10

• Assignee: Unassigned
• Reporter: Nicolas PHUNG
• Created: 08/Apr/15 15:50
• Updated: 10/Apr/15 14:51
• Resolved: 09/Apr/15 13:45

Description

This is the Avro Schema (OLD) I was using to write Avro binary data before:

{
    "namespace": "com.hello.world",
    "type": "record",
    "name": "Toto",
    "fields": [
        {
            "name": "a",
            "type": [
                "string",
                "null"
            ]
        },
        {
            "name": "b",
            "type": "string"
        }
    ]
}

This is the Avro Schema (NEW) I'm using to read the Avro binary data :

{
    "namespace": "com.hello.world",
    "type": "record",
    "name": "Toto",
    "fields": [
        {
            "name": "a",
            "type": [
                "string",
                "null"
            ]
        },
        {
            "name": "b",
            "type": "string"
        },
        {
            "name": "c",
            "type": "string",
            "default": "na"
        }
    ]
}

However, I can't read the old data with the new Schema. I've got the following errors :

15/04/08 17:32:22 ERROR executor.Executor: Exception in task 0.0 in stage 3.0 (TID 3)
java.io.EOFException
	at org.apache.avro.io.BinaryDecoder.ensureBounds(BinaryDecoder.java:473)
	at org.apache.avro.io.BinaryDecoder.readInt(BinaryDecoder.java:128)
	at org.apache.avro.io.BinaryDecoder.readString(BinaryDecoder.java:259)
	at org.apache.avro.io.BinaryDecoder.readString(BinaryDecoder.java:272)
	at org.apache.avro.io.ValidatingDecoder.readString(ValidatingDecoder.java:113)
	at org.apache.avro.generic.GenericDatumReader.readString(GenericDatumReader.java:353)
	at org.apache.avro.generic.GenericDatumReader.read(GenericDatumReader.java:157)
	at org.apache.avro.generic.GenericDatumReader.readField(GenericDatumReader.java:193)
	at org.apache.avro.generic.GenericDatumReader.readRecord(GenericDatumReader.java:183)
	at org.apache.avro.generic.GenericDatumReader.read(GenericDatumReader.java:151)
	at org.apache.avro.generic.GenericDatumReader.read(GenericDatumReader.java:142)
	at com.miguno.kafka.avro.AvroDecoder.fromBytes(AvroDecoder.scala:31)

From my understanding, I should be able to read the old data with the new schema that contains a new field with a default value. But it doesn't seem to work. Am I doing something wrong ?

Issue Links

• duplicates: AVRO-1124 RESTful service for holding schemas