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Hadoop QA commented on HADOOP-2486: ----------------------------------- -1 overall. Here are the results of testing the latest attachment http://issues.apache.org/jira/secure/attachment/12372141/2486.patch against trunk revision r606333. @author +1. The patch does not contain any @author tags. javadoc +1. The javadoc tool did not generate any warning messages. javac +1. The applied patch does not generate any new compiler warnings. findbugs +1. The patch does not introduce any new Findbugs warnings. core tests +1. The patch passed core unit tests. contrib tests -1. The patch failed contrib unit tests. Test results: http://lucene.zones.apache.org:8080/hudson/job/Hadoop-Patch/1423/testReport/ Findbugs warnings: http://lucene.zones.apache.org:8080/hudson/job/Hadoop-Patch/1423/artifact/trunk/build/test/findbugs/newPatchFindbugsWarnings.html Checkstyle results: http://lucene.zones.apache.org:8080/hudson/job/Hadoop-Patch/1423/artifact/trunk/build/test/checkstyle-errors.html Console output: http://lucene.zones.apache.org:8080/hudson/job/Hadoop-Patch/1423/console This message is automatically generated. > Dropping records at reducer. InMemoryFileSystem NPE. > ----------------------------------------------------- > > Key: HADOOP-2486 > URL: https://issues.apache.org/jira/browse/HADOOP-2486 > Project: Hadoop > Issue Type: Bug > Components: mapred > Affects Versions: 0.14.3 > Reporter: Koji Noguchi > Assignee: Devaraj Das > Attachments: 2486.patch > > > Note: I'm really not sure if this is a bug in my code or in mapred. > With my mapreduce job without combiner, I sometimes see # of total Map > output records != # of total Reduce input records. What's weird to me is, > when I rerun my code with exact same input, usually I get an expected #map > output recs == #reduce output recs. > Both jobs finish successfully. No failed tasks. No speculative execution. > I ran separate linecount mapred jobs on both the input and the output to see > if the counters are reporting the correct number. > When I looked at all the 513 reducer counter, I found single reducer with > different counts for the two runs. > Only error stood out in that reducer userlog is, > {noformat} > 2007-12-22 00:19:07,640 INFO org.apache.hadoop.mapred.ReduceTask: > task_200712220008_0003_r_000024_0 done copying > task_200712220008_0003_m_000288_0 output from qqq856.ppp.com. > 2007-12-22 00:19:07,640 INFO org.apache.hadoop.mapred.ReduceTask: > task_200712220008_0003_r_000024_0 Copying task_200712220008_0003_m_000327_0 > output from qqq887.ppp.com. > 2007-12-22 00:19:07,640 ERROR org.apache.hadoop.mapred.ReduceTask: Map output > copy failure: java.lang.NullPointerException > at > org.apache.hadoop.fs.InMemoryFileSystem$RawInMemoryFileSystem$FileAttributes.access$300(InMemoryFileSystem.java:366) > at > org.apache.hadoop.fs.InMemoryFileSystem$RawInMemoryFileSystem$InMemoryFileStatus.(InMemoryFileSystem.java:380) > at > org.apache.hadoop.fs.InMemoryFileSystem$RawInMemoryFileSystem.getFileStatus(InMemoryFileSystem.java:283) > at org.apache.hadoop.fs.FileSystem.isDirectory(FileSystem.java:423) > at > org.apache.hadoop.fs.ChecksumFileSystem.rename(ChecksumFileSystem.java:386) > at > org.apache.hadoop.mapred.ReduceTask$ReduceCopier$MapOutputCopier.copyOutput(ReduceTask.java:716) > at > org.apache.hadoop.mapred.ReduceTask$ReduceCopier$MapOutputCopier.run(ReduceTask.java:637) > 2007-12-22 00:19:07,641 INFO org.apache.hadoop.mapred.ReduceTask: > task_200712220008_0003_r_000024_0 done copying > task_200712220008_0003_m_000228_0 output from qqq801.ppp.com. > 2007-12-22 00:19:07,641 INFO org.apache.hadoop.mapred.ReduceTask: > task_200712220008_0003_r_000024_0 Copying task_200712220008_0003_m_000337_0 > output from qqq841.ppp.com. > {noformat} > Could this error be somehow related to my having different # of records? -- This message is automatically generated by JIRA. - You can reply to this email to add a comment to the issue online.