[PIG-5372] SAMPLE/RANDOM(udf) before skewed join failing with NPE

• Type: Bug
• Status: Resolved
• Priority: Major
• Resolution: Fixed
• Affects Version/s: 0.16.0
• Fix Version/s: 0.17.1
• Hadoop Flags: Reviewed
• Assignee: Koji Noguchi
• Reporter: Koji Noguchi
• Created: 12/Dec/18 21:07
• Updated: 25/Jan/19 21:53
• Resolved: 25/Jan/19 21:53

Description

Sample short code like below

A = LOAD 'input.txt' AS (a1:int, a2:chararray, a3:int);
B = LOAD 'input.txt' AS (b1:int, b2:chararray, b3:int);

A2 = FOREACH A generate *, RANDOM() as randnum;

D = join A2 by a1, B by b1 using 'skewed' parallel 2;

store D into '$output';

Fails with NPE.

2018-12-12 16:06:04,860 [Dispatcher thread: Central] INFO  org.apache.tez.dag.history.HistoryEventHandler - [HISTORY][DAG:dag_1544648742542_0001_1][Event:TASK_FINISHED]: vertexName=scope-55, taskId=task_1544648742542_0001_1_02_000000, startTime=1544648745036, finishTime=1544648764857, timeTaken=19821, status=KILLED, successfulAttemptID=null, diagnostics=TaskAttempt 0 failed, info=[Error: Failure while running task:org.apache.pig.backend.executionengine.ExecException: ERROR 0: Exception while executing (Name: Local Rearrange[tuple]{int}(false) - scope-29 ->       scope-58 Operator Key: scope-29): org.apache.pig.backend.executionengine.ExecException: ERROR 0: Exception while executing [POUserFunc (Name: POUserFunc(org.apache.pig.builtin.RANDOM)[double] - scope-40 Operator Key: scope-40) children: null at []]: java.lang.NullPointerException
        at org.apache.pig.backend.hadoop.executionengine.physicalLayer.PhysicalOperator.processInput(PhysicalOperator.java:315)
        at org.apache.pig.backend.hadoop.executionengine.physicalLayer.relationalOperators.POLocalRearrange.getNextTuple(POLocalRearrange.java:287)
        at org.apache.pig.backend.hadoop.executionengine.tez.plan.operator.POLocalRearrangeTez.getNextTuple(POLocalRearrangeTez.java:131)
        at org.apache.pig.backend.hadoop.executionengine.tez.runtime.PigProcessor.runPipeline(PigProcessor.java:420)
        at org.apache.pig.backend.hadoop.executionengine.tez.runtime.PigProcessor.run(PigProcessor.java:282)
        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$1.run(TezTaskRunner.java:171)
        at java.security.AccessController.doPrivileged(Native Method)
        at javax.security.auth.Subject.doAs(Subject.java:422)
        at org.apache.hadoop.security.UserGroupInformation.doAs(UserGroupInformation.java:1698)
        at org.apache.tez.runtime.task.TezTaskRunner$TaskRunnerCallable.callInternal(TezTaskRunner.java:171)
        at org.apache.tez.runtime.task.TezTaskRunner$TaskRunnerCallable.callInternal(TezTaskRunner.java:167)
        at org.apache.tez.common.CallableWithNdc.call(CallableWithNdc.java:36)
        at java.util.concurrent.FutureTask.run(FutureTask.java:266)
        at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1142)
        at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:617)
        at java.lang.Thread.run(Thread.java:745)
Caused by: org.apache.pig.backend.executionengine.ExecException: ERROR 0: Exception while executing [POUserFunc (Name: POUserFunc(org.apache.pig.builtin.RANDOM)[double] - scope-40 Operator Key: scope-40) children: null at []]: java.lang.NullPointerException
        at org.apache.pig.backend.hadoop.executionengine.physicalLayer.PhysicalOperator.getNext(PhysicalOperator.java:367)
        at org.apache.pig.backend.hadoop.executionengine.physicalLayer.relationalOperators.POForEach.processPlan(POForEach.java:408)
        at org.apache.pig.backend.hadoop.executionengine.physicalLayer.relationalOperators.POForEach.getNextTuple(POForEach.java:325)
        at org.apache.pig.backend.hadoop.executionengine.physicalLayer.PhysicalOperator.processInput(PhysicalOperator.java:305)
        ... 17 more
Caused by: java.lang.NullPointerException
        at org.apache.pig.builtin.RANDOM.exec(RANDOM.java:51)
        at org.apache.pig.builtin.RANDOM.exec(RANDOM.java:37)
        at org.apache.pig.backend.hadoop.executionengine.physicalLayer.expressionOperators.POUserFunc.getNext(POUserFunc.java:332)
        at org.apache.pig.backend.hadoop.executionengine.physicalLayer.expressionOperators.POUserFunc.getNextDouble(POUserFunc.java:396)
        at org.apache.pig.backend.hadoop.executionengine.physicalLayer.PhysicalOperator.getNext(PhysicalOperator.java:343)
        ... 20 more
]