[PIG-4816] Read a null scalar causing a Tez failure

• Type: Bug
• Status: Closed
• Priority: Major
• Resolution: Fixed
• Fix Version/s: 0.16.0
• Hadoop Flags: Reviewed
• Assignee: Daniel Dai
• Reporter: Daniel Dai
• Created: 26/Feb/16 23:47
• Updated: 08/Jun/16 20:48
• Resolved: 01/Mar/16 22:48

Description

The following script fail:

a = load 'studenttab10k' as (name:chararray, age:int, gpa:double);
b = filter a by age > 100;
c = group b all;
d = foreach c generate COUNT(b.gpa) as count;
e = foreach a generate (d.count IS NOT NULL? d.count : 0l);
dump e;

Error stack:

Failure while running task:org.apache.pig.backend.executionengine.ExecException: ERROR 0: java.io.IOException: Please check if you are invoking next() even after it returned false. For usage, please refer to KeyValueReader javadocs
	at org.apache.pig.backend.hadoop.executionengine.tez.plan.udf.ReadScalarsTez.attachInputs(ReadScalarsTez.java:96)
	at org.apache.pig.backend.hadoop.executionengine.tez.runtime.PigProcessor.initializeInputs(PigProcessor.java:295)
	at org.apache.pig.backend.hadoop.executionengine.tez.runtime.PigProcessor.run(PigProcessor.java:183)
	at org.apache.tez.runtime.LogicalIOProcessorRuntimeTask.run(LogicalIOProcessorRuntimeTask.java:337)
	at org.apache.tez.runtime.task.TezTaskRunner$TaskRunnerCallable$1.run(TezTaskRunner.java:179)
	at org.apache.tez.runtime.task.TezTaskRunner$TaskRunnerCallable$1.run(TezTaskRunner.java:171)
	at java.security.AccessController.doPrivileged(Native Method)
	at javax.security.auth.Subject.doAs(Subject.java:415)
	at org.apache.hadoop.security.UserGroupInformation.doAs(UserGroupInformation.java:1628)
	at org.apache.tez.runtime.task.TezTaskRunner$TaskRunnerCallable.callInternal(TezTaskRunner.java:171)
	at org.apache.tez.runtime.task.TezTaskRunner$TaskRunnerCallable.callInternal(TezTaskRunner.java:167)
	at org.apache.tez.common.CallableWithNdc.call(CallableWithNdc.java:36)
	at java.util.concurrent.FutureTask.run(FutureTask.java:262)
	at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1145)
	at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:615)
	at java.lang.Thread.run(Thread.java:745)
Caused by: java.io.IOException: Please check if you are invoking next() even after it returned false. For usage, please refer to KeyValueReader javadocs
	at org.apache.tez.runtime.library.api.KeyValueReader.hasCompletedProcessing(KeyValueReader.java:77)
	at org.apache.tez.runtime.library.common.readers.UnorderedKVReader.moveToNextInput(UnorderedKVReader.java:190)
	at org.apache.tez.runtime.library.common.readers.UnorderedKVReader.next(UnorderedKVReader.java:118)
	at org.apache.pig.backend.hadoop.executionengine.tez.plan.udf.ReadScalarsTez.attachInputs(ReadScalarsTez.java:81)
	... 15 more