Christon DeWan created PIG-3469:
-----------------------------------
Summary: Skewed join can cause unrecoverable NullPointerException
when one of its inputs is missing.
Key: PIG-3469
URL: https://issues.apache.org/jira/browse/PIG-3469
Project: Pig
Issue Type: Bug
Affects Versions: 0.11
Environment: Apache Pig version 0.11.0-cdh4.4.0
Happens in both local execution environment (os x) and cluster environment
(linux)
Reporter: Christon DeWan
Run this script in the local execution environment (affects cluster mode too):
{{
%declare DATA_EXISTS /tmp/test_data_exists.tsv
%declare DATA_MISSING /tmp/test_data_missing.tsv
%declare DUMMY `bash -c '(for (( i=0; \$i < 10; i++ )); do echo \$i; done) >
/tmp/test_data_exists.tsv; true'`
exists = LOAD '$DATA_EXISTS' AS (a:long);
missing = LOAD '$DATA_MISSING' AS (a:long);
missing = FOREACH ( GROUP missing BY a ) GENERATE $0 AS a, COUNT_STAR($1);
joined = JOIN exists BY a, missing BY a USING 'skewed';
STORE joined INTO '/tmp/test_out.tsv';
}}
Results in NullPointerException which halts entire pig execution, including
unrelated jobs. Expected: only dependencies of the error'd LOAD statement
should fail.
Error:
{{
2013-09-18 11:42:31,518 [main] ERROR org.apache.pig.tools.grunt.Grunt - ERROR
2017: Internal error creating job configuration.
2013-09-18 11:42:31,518 [main] ERROR org.apache.pig.tools.grunt.Grunt -
org.apache.pig.backend.hadoop.executionengine.mapReduceLayer.JobCreationException:
ERROR 2017: Internal error creating job configuration.
at
org.apache.pig.backend.hadoop.executionengine.mapReduceLayer.JobControlCompiler.getJob(JobControlCompiler.java:848)
at
org.apache.pig.backend.hadoop.executionengine.mapReduceLayer.JobControlCompiler.compile(JobControlCompiler.java:294)
at
org.apache.pig.backend.hadoop.executionengine.mapReduceLayer.MapReduceLauncher.launchPig(MapReduceLauncher.java:177)
at org.apache.pig.PigServer.launchPlan(PigServer.java:1266)
at
org.apache.pig.PigServer.executeCompiledLogicalPlan(PigServer.java:1251)
at org.apache.pig.PigServer.execute(PigServer.java:1241)
at org.apache.pig.PigServer.executeBatch(PigServer.java:335)
at
org.apache.pig.tools.grunt.GruntParser.executeBatch(GruntParser.java:137)
at
org.apache.pig.tools.grunt.GruntParser.parseStopOnError(GruntParser.java:198)
at
org.apache.pig.tools.grunt.GruntParser.parseStopOnError(GruntParser.java:170)
at org.apache.pig.tools.grunt.Grunt.exec(Grunt.java:84)
at org.apache.pig.Main.run(Main.java:604)
at org.apache.pig.Main.main(Main.java:157)
at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
at
sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:39)
at
sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:25)
at java.lang.reflect.Method.invoke(Method.java:597)
at org.apache.hadoop.util.RunJar.main(RunJar.java:208)
Caused by: java.lang.NullPointerException
at
org.apache.pig.backend.hadoop.executionengine.mapReduceLayer.JobControlCompiler.adjustNumReducers(JobControlCompiler.java:868)
at
org.apache.pig.backend.hadoop.executionengine.mapReduceLayer.JobControlCompiler.getJob(JobControlCompiler.java:480)
... 17 more
}}
Script above is as small as I can make it while still reproducing the issue.
Removing the group-foreach causes the join to fail harmlessly (not stopping pig
execution), as does using the default join. Did not occur on 0.10.1.
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