The JIRA https://issues.apache.org/jira/browse/MAPREDUCE-2584 should help such cases, if what I speculated above is indeed the case.
On Fri, Feb 8, 2013 at 12:16 AM, Harsh J <[email protected]> wrote: > Thanks, I managed to correlate proper line numbers. > > Are you using some form of custom serialization in your job code? That > is, are your keys non-Writable types and are of some other type? The > specific NPE is arising from the SerializationFactory not being able > to find a serializer for your Map-Output key class. You may want to > look into that direction, or share your code for the list to spot it > instead. > > On Fri, Feb 8, 2013 at 12:11 AM, Ravi Chandran > <[email protected]> wrote: >> hi, >> >> it is Hadoop 2.0.0-cdh4.1.1. the whole output is given below: >> >> Hadoop 2.0.0-cdh4.1.1 >> Subversion >> file:///data/1/jenkins/workspace/generic-package-centos32-6/topdir/BUILD/hadoop-2.0.0-cdh4.1.1/src/hadoop-common-project/hadoop-common >> -r 581959ba23e4af85afd8db98b7687662fe9c5f20 >> >> >> >> On Fri, Feb 8, 2013 at 12:04 AM, Harsh J <[email protected]> wrote: >>> >>> Hey Ravi, >>> >>> What version of Hadoop is this exactly? (Type and send output of >>> "hadoop version" if unsure) >>> >>> On Thu, Feb 7, 2013 at 11:55 PM, Ravi Chandran >>> <[email protected]> wrote: >>> > Hi, >>> > >>> > I am trying to do a name sorting using secondary sort. I have a working >>> > example, which I am taking as a reference. But I am getting a null >>> > pointer >>> > error in the MapTask class. I am not able to locate the reason. as the >>> > logic >>> > to create the Custom Object from a given file has been tested through a >>> > java >>> > class.. >>> > I am getting this error: >>> > >>> > 13/02/07 12:23:42 WARN snappy.LoadSnappy: Snappy native library is >>> > available >>> > 13/02/07 12:23:42 INFO snappy.LoadSnappy: Snappy native library loaded >>> > 13/02/07 12:23:42 INFO mapred.FileInputFormat: Total input paths to >>> > process >>> > : 1 >>> > 13/02/07 12:23:43 INFO mapred.JobClient: Running job: >>> > job_201301301056_0014 >>> > 13/02/07 12:23:44 INFO mapred.JobClient: map 0% reduce 0% >>> > 13/02/07 12:23:56 INFO mapred.JobClient: Task Id : >>> > attempt_201301301056_0014_m_000000_0, Status : FAILED >>> > java.lang.NullPointerException >>> > at >>> > >>> > org.apache.hadoop.mapred.MapTask$MapOutputBuffer.<init>(MapTask.java:814) >>> > at org.apache.hadoop.mapred.MapTask.runOldMapper(MapTask.java:385) >>> > at org.apache.hadoop.mapred.MapTask.run(MapTask.java:327) >>> > at org.apache.hadoop.mapred.Child$4.run(Child.java:268) >>> > at java.security.AccessController.doPrivileged(Native Method) >>> > at javax.security.auth.Subject.doAs(Subject.java:396) >>> > at >>> > >>> > org.apache.hadoop.security.UserGroupInformation.doAs(UserGroupInformation.java:1332) >>> > at org.apache.hadoop.mapred.Child.main(Child.java:262) >>> > 13/02/07 12:23:57 INFO mapred.JobClient: Task Id : >>> > attempt_201301301056_0014_m_000001_0, Status : FAILED >>> > java.lang.NullPointerException >>> > at >>> > >>> > org.apache.hadoop.mapred.MapTask$MapOutputBuffer.<init>(MapTask.java:814) >>> > at org.apache.hadoop.mapred.MapTask.runOldMapper(MapTask.java:385) >>> > at org.apache.hadoop.mapred.MapTask.run(MapTask.java:327) >>> > at org.apache.hadoop.mapred.Child$4.run(Child.java:268) >>> > at java.security.AccessController.doPrivileged(Native Method) >>> > at javax.security.auth.Subject.doAs(Subject.java:396) >>> > at >>> > >>> > org.apache.hadoop.security.UserGroupInformation.doAs(UserGroupInformation.java:1332) >>> > at org.apache.hadoop.mapred.Child.main(Child.java:262) >>> > >>> > I am giving the Mapper code below: >>> > >>> > import java.io.IOException; >>> > import org.apache.hadoop.io.LongWritable; >>> > import org.apache.hadoop.io.Text; >>> > import org.apache.hadoop.mapred.MapReduceBase; >>> > import org.apache.hadoop.mapred.Mapper; >>> > import org.apache.hadoop.mapred.OutputCollector; >>> > import org.apache.hadoop.mapred.Reporter; >>> > import org.apache.log4j.Logger; >>> > import com.pom.Name; >>> > >>> > public class StubMapper extends MapReduceBase implements >>> > Mapper<LongWritable, Text, Name, Text> { >>> > >>> > private static Logger logger = >>> > Logger.getLogger(StubMapper.class.getName()); >>> > >>> > StringBuffer readLine = new StringBuffer(); >>> > private final Name name = new Name(); >>> > @Override >>> > public void map(LongWritable key, Text value, >>> > OutputCollector<Name, Text> output, Reporter reporter) >>> > throws IOException { >>> > String line = value.toString(); >>> > String[] packer = null; >>> > >>> > packer = line.split(" "); >>> > >>> > // create the object >>> > if(packer.length>2) >>> > { >>> > // take everything except last name >>> > for (int i = 0; i < packer.length-1; i++) { >>> > readLine.append(packer[i]+" "); >>> > } >>> > >>> > name.setfName(readLine.toString()); >>> > name.setlName(packer[packer.length-1]); >>> > >>> > //clear the variable >>> > readLine.delete(0, readLine.length()); >>> > } >>> > else if(packer.length>0) >>> > { >>> > name.setfName(packer[0]); >>> > name.setlName(packer[1]); >>> > } >>> > >>> > output.collect(name, new Text(name.getlName())); >>> > >>> > } >>> > } >>> > >>> > I am not able to figure out the possible cause.. >>> > >>> > -- >>> > Thanks & Regards >>> > Ravi >>> >>> >>> >>> -- >>> Harsh J >> >> >> >> >> -- >> Thanks & Regards >> Ravi > > > > -- > Harsh J -- Harsh J
