[PIG-619] Dumping empty results produces "Unable to get results for /tmp/temp-1964806069/tmp256878619 org.apache.pig.builtin.BinStorage" message

• Type: Bug
• Status: Closed
• Priority: Major
• Resolution: Fixed
• Affects Version/s: 0.2.0
• Fix Version/s: 0.3.0
• Component/s: impl

Environment

Hadoop 18, Multi-node hadoop installation

• Assignee: Alan Gates
• Reporter: Viraj Bhat
• Created: 13/Jan/09 22:30
• Updated: 24/Mar/10 22:10
• Resolved: 28/May/09 17:17

Description

Following pig script stores empty filter results into 'emptyfilteredlogs' HDFS dir. It later reloads this data from an empty HDFS dir for additional grouping and counting. It has been observed that this script, succeeds on a single node hadoop installation with the following message as the alias COUNT_EMPTYFILTERED_LOGS contains empty data.
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2009-01-13 21:47:08,988 [main] INFO org.apache.pig.backend.hadoop.executionengine.mapReduceLayer.MapReduceLauncher - Success!
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But on a multi-node Hadoop installation, the script fails with the following error:
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2009-01-13 13:48:34,602 [main] INFO org.apache.pig.backend.hadoop.executionengine.mapReduceLayer.MapReduceLauncher - Success!
java.io.IOException: Unable to open iterator for alias: COUNT_EMPTYFILTERED_LOGS [Unable to get results for /tmp/temp-1964806069/tmp256878619:org.apache.pig.builtin.BinStorage]
at org.apache.pig.backend.hadoop.executionengine.HJob.getResults(HJob.java:74)
at org.apache.pig.PigServer.openIterator(PigServer.java:408)
at org.apache.pig.tools.grunt.GruntParser.processDump(GruntParser.java:269)
at org.apache.pig.tools.pigscript.parser.PigScriptParser.parse(PigScriptParser.java:178)
at org.apache.pig.tools.grunt.GruntParser.parseStopOnError(GruntParser.java:84)
at org.apache.pig.tools.grunt.Grunt.exec(Grunt.java:64)
at org.apache.pig.Main.main(Main.java:306)
Caused by: org.apache.pig.backend.executionengine.ExecException: Unable to get results for /tmp/temp-1964806069/tmp256878619:org.apache.pig.builtin.BinStorage
... 7 more
Caused by: java.io.IOException: /tmp/temp-1964806069/tmp256878619 does not exist
at org.apache.pig.impl.io.FileLocalizer.openDFSFile(FileLocalizer.java:188)
at org.apache.pig.impl.io.FileLocalizer.open(FileLocalizer.java:291)
at org.apache.pig.backend.hadoop.executionengine.HJob.getResults(HJob.java:69)
... 6 more
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RAW_LOGS = load 'mydata.txt' as (url:chararray, numvisits:int);
RAW_LOGS = limit RAW_LOGS 2;
FILTERED_LOGS = filter RAW_LOGS by numvisits < 0;
store FILTERED_LOGS into 'emptyfilteredlogs' using PigStorage();
EMPTY_FILTERED_LOGS = load 'emptyfilteredlogs' as (url:chararray, numvisits:int);
GROUP_EMPTYFILTERED_LOGS = group EMPTY_FILTERED_LOGS by numvisits;
COUNT_EMPTYFILTERED_LOGS = foreach GROUP_EMPTYFILTERED_LOGS generate
                             group, COUNT(EMPTY_FILTERED_LOGS);
explain COUNT_EMPTYFILTERED_LOGS;
dump COUNT_EMPTYFILTERED_LOGS;