Hi Thejas, you suggested that there might be something wrong with Hadoop configuration itself.
My other mapreduce jobs are running fine. I am able to run word-count example etc. Only PIG jobs are failing. Any ideas? ________________________________ From: Thejas M Nair [mailto:[email protected]] Sent: Monday, December 13, 2010 7:32 PM To: [email protected]; Deepak Choudhary N (WT01 - Product Engineering Services) Subject: Re: ERROR 6015: During execution, encountered a Hadoop error | ERROR 1066: Unable to open iterator for alias grouped_records >From the job tracker web UI, you should be able see the MR job run by this pig >query. If you follow the links, you should be able to find the reduce task >logs. Thanks, Thejas On 12/13/10 5:11 AM, "[email protected]" <[email protected]> wrote: My Script: records = LOAD 'hdfs://hadoop.namenode:54310/data' USING PigStorage(',') AS (Year:int, Month:int,DayofMonth:int,DayofWeek:int); grouped_records = GROUP records BY Month; DUMP grouped_records; Hadoop Version: 0.20.2 Pig Version: 0.7.0 I couldn't find the reduce task logs. Where are they generated? Surprisingly, PIG jobs donot seem to generate any Hadoop (namenode, datanode, tasktracker etc) logs. -----Original Message----- From: Dmitriy Ryaboy [mailto:[email protected]] Sent: Monday, December 13, 2010 4:51 PM To: [email protected] Subject: Re: ERROR 6015: During execution, encountered a Hadoop error | ERROR 1066: Unable to open iterator for alias grouped_records Can you send along your script and the reduce task logs? What version of Pig and Hadoop are you using? Thanks, -Dmitriy On Sun, Dec 12, 2010 at 10:36 PM, <[email protected]> wrote: > Hi, > > I loaded a csv file with about 10 fields into PigStorage and tried to > do a GROUP BY on one of the fields. The MapReduce job gets created, > and the Mappers finish execution. > > But after that, the job fails with the following error messages: > > 2010-12-13 10:31:08,902 [main] INFO > > org.apache.pig.backend.hadoop.executionengine.mapReduceLayer.MapReduce > Launcher > - 100% complete > 2010-12-13 10:31:08,902 [main] ERROR > org.apache.pig.backend.hadoop.executionengine.mapReduceLayer.MapReduce > Launcher > - 1 map reduce job(s) failed! > 2010-12-13 10:31:08,911 [main] ERROR > org.apache.pig.backend.hadoop.executionengine.mapReduceLayer.MapReduce > Launcher > - Failed to produce result in: > "hdfs://hadoop.namenode:54310/tmp/temp2041073534/tmp-2060206542" > 2010-12-13 10:31:08,911 [main] INFO > > org.apache.pig.backend.hadoop.executionengine.mapReduceLayer.MapReduce > Launcher > - Failed! > 2010-12-13 10:31:08,961 [main] ERROR org.apache.pig.tools.grunt.Grunt > - ERROR 6015: During execution, encountered a Hadoop error. > 2010-12-13 10:31:08,961 [main] ERROR org.apache.pig.tools.grunt.Grunt > - > org.apache.pig.impl.logicalLayer.FrontendException: ERROR 1066: Unable > to open iterator for alias grouped_records > at org.apache.pig.PigServer.openIterator(PigServer.java:521) > at > org.apache.pig.tools.grunt.GruntParser.processDump(GruntParser.java:544) > at > org.apache.pig.tools.pigscript.parser.PigScriptParser.parse(PigScriptParser.java:241) > at > org.apache.pig.tools.grunt.GruntParser.parseStopOnError(GruntParser.java:162) > at > org.apache.pig.tools.grunt.GruntParser.parseStopOnError(GruntParser.java:138) > at org.apache.pig.tools.grunt.Grunt.run(Grunt.java:75) > at org.apache.pig.Main.main(Main.java:357) > Caused by: org.apache.pig.backend.executionengine.ExecException: ERROR > 6015: During execution, encountered a Hadoop error. > at > .util.concurrent.ConcurrentHashMap.get(ConcurrentHashMap.java:768) > at > .apache.hadoop.mapred.ReduceTask(ReduceCopier$GetMapEventsThread.getMa > pCompletionEvents(ReduceTask.java:2683) > Caused by: java.lang.NullPointerException > ... 2 more > > The filter statements (Mapper only) work properly, so it's not that > nothing is running. > > What's the issue here? > > Please do not print this email unless it is absolutely necessary. > > The information contained in this electronic message and any > attachments to this message are intended for the exclusive use of the > addressee(s) and may contain proprietary, confidential or privileged > information. 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