[AVRO-2042] Can't reliably write decimal/BigDecimal values to file

• Type: Bug
• Status: Resolved
• Priority: Major
• Resolution: Not A Problem
• Affects Version/s: 1.8.2
• Assignee: Ryan Blue
• Reporter: Fred Cohen
• Created: 15/Jun/17 16:28
• Updated: 15/Jun/17 18:15
• Resolved: 15/Jun/17 16:39

Description

Attempting to write some decimal values fails.

Here's the schema I created for this test:

{
"namespace":"org.test",
"type": "record",
"name": "DecimalTest",
"fields": [

{
"name": "decimalVal",
"type":

{"type": "bytes", "logicalType":"decimal","precision": 6, "scale": 4}

}
]
}

The problem is that to my knowledge I can't control the scale used by BigDecimal.
While the first value uses a scale of 4, the second one is scale 0.

decimals.add(new BigDecimal(12.01F, mathContext));
decimals.add(new BigDecimal(12.00F, mathContext));

It leads to these errors during the write operation:

org.apache.avro.file.DataFileWriter$AppendWriteException: org.apache.avro.AvroTypeException: Cannot encode decimal with scale 0 as scale 4

at org.apache.avro.file.DataFileWriter.append(DataFileWriter.java:308)
at AvroDecimalTest.writeDecimalTest(AvroDecimalTest.java:67)
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:497)
at org.junit.runners.model.FrameworkMethod$1.runReflectiveCall(FrameworkMethod.java:44)
at org.junit.internal.runners.model.ReflectiveCallable.run(ReflectiveCallable.java:15)
at org.junit.runners.model.FrameworkMethod.invokeExplosively(FrameworkMethod.java:41)
at org.junit.internal.runners.statements.InvokeMethod.evaluate(InvokeMethod.java:20)
at org.junit.runners.BlockJUnit4ClassRunner.runNotIgnored(BlockJUnit4ClassRunner.java:79)
at org.junit.runners.BlockJUnit4ClassRunner.runChild(BlockJUnit4ClassRunner.java:71)
at org.junit.runners.BlockJUnit4ClassRunner.runChild(BlockJUnit4ClassRunner.java:49)
at org.junit.runners.ParentRunner$3.run(ParentRunner.java:193)
at org.junit.runners.ParentRunner$1.schedule(ParentRunner.java:52)
at org.junit.runners.ParentRunner.runChildren(ParentRunner.java:191)
at org.junit.runners.ParentRunner.access$000(ParentRunner.java:42)
at org.junit.runners.ParentRunner$2.evaluate(ParentRunner.java:184)
at org.junit.runners.ParentRunner.run(ParentRunner.java:236)
at org.junit.runner.JUnitCore.run(JUnitCore.java:157)
at com.intellij.junit4.JUnit4IdeaTestRunner.startRunnerWithArgs(JUnit4IdeaTestRunner.java:68)
at com.intellij.rt.execution.junit.IdeaTestRunner$Repeater.startRunnerWithArgs(IdeaTestRunner.java:51)
at com.intellij.rt.execution.junit.JUnitStarter.prepareStreamsAndStart(JUnitStarter.java:237)
at com.intellij.rt.execution.junit.JUnitStarter.main(JUnitStarter.java:70)
Caused by: org.apache.avro.AvroTypeException: Cannot encode decimal with scale 0 as scale 4
at org.apache.avro.Conversions$DecimalConversion.toBytes(Conversions.java:92)
at org.apache.avro.Conversions$DecimalConversion.toBytes(Conversions.java:62)
at org.apache.avro.Conversions.convertToRawType(Conversions.java:218)
at org.apache.avro.generic.GenericDatumWriter.convert(GenericDatumWriter.java:95)
at org.apache.avro.specific.SpecificDatumWriter.writeField(SpecificDatumWriter.java:84)
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.avro.file.DataFileWriter.append(DataFileWriter.java:302)
... 23 more