[
https://issues.apache.org/jira/browse/PIG-619?page=com.atlassian.jira.plugin.system.issuetabpanels:all-tabpanel
]
Alan Gates updated PIG-619:
---------------------------
Fix Version/s: 0.3.0
Status: Patch Available (was: Open)
In order to see this behavior, you need three map reduce jobs, something like:
A = load
B = filter everything out
C = group
D = foreach
E = distinct
F = group
G = foreach
store G
In this case the first job (A-D) will run and produce 0 length part files. The
second job (E) will run, but no maps will be started because the files are zero
length. As a result Hadoop now seems to create no output files for this second
job. The third job (F-G) then fails complaining that the input files don't
exist. The patch changes pig's slicer to return at least one input split per
part file even when the file is zero length.
> Dumping empty results produces "Unable to get results for
> /tmp/temp-1964806069/tmp256878619 org.apache.pig.builtin.BinStorage" message
> ---------------------------------------------------------------------------------------------------------------------------------------
>
> Key: PIG-619
> URL: https://issues.apache.org/jira/browse/PIG-619
> Project: Pig
> Issue Type: Bug
> Components: impl
> Affects Versions: 0.2.0
> Environment: Hadoop 18, Multi-node hadoop installation
> Reporter: Viraj Bhat
> Assignee: Alan Gates
> Fix For: 0.3.0
>
> Attachments: mydata.txt, PIG-619.patch, tmpfileload.pig
>
>
> 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.
> ==============================================================================================================
> 2009-01-13 21:47:08,988 [main] INFO
> org.apache.pig.backend.hadoop.executionengine.mapReduceLayer.MapReduceLauncher
> - Success!
> ==============================================================================================================
> But on a multi-node Hadoop installation, the script fails with the following
> error:
> ==============================================================================================================
> 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
> ==============================================================================================================
> {code}
> 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;
> {code}
--
This message is automatically generated by JIRA.
-
You can reply to this email to add a comment to the issue online.
