Problem resolved!! This looks like a bug in 0.12.0 version (there is some thread in the developer area regarding a race-condition which results in the hung reduce job) . I moved back to 0.11.2 and this got resolved! Thanks a lot to all of you and specially Jaya for pointing it out.
regards gaurav Gaurav Agarwal wrote: > > Hi Everyone! > I am new user to Hadoop and trying to set up a small cluster using Hadoop > (Release Mar 02) on Ubuntu 6.10 (Edgy) ; but I am facing some issues doing > that. > > I am trying to run the Hadoop 'wordcount' example program which come > bundled with it. I am able to successfully run the program on a single > node cluster (that is using my local machine only). But, when I try to run > the same program on a cluster of two machines, the program hangs in the > 'reduce' phase. > > > Settings: > > Master Node: 192.168.1.150 (dennis-laptop) > Slave Node: 192.168.1.201 (traal) > > User Account on both Master and Slave is named : Hadoop > > Password-less ssh login to Slave from the Master is working. > > JAVA_HOME is set appropriately in the hadoop-env.sh file on both > Master/Slave. > > MASTER > > 1) conf/slaves > localhost > [EMAIL PROTECTED] > > 2) conf/master > localhost > > 3) conf/hadoop-site.xml > <?xml version="1.0"?> > <?xml-stylesheet type="text/xsl" href="configuration.xsl"?> > > <!-- Put site-specific property overrides in this file. --> > > <configuration> > <property> > <name>fs.default.name</name> > <value>192.168.1.150:50000</value> > </property> > > <property> > <name>mapred.job.tracker</name> > <value>192.168.1.150:50001</value> > </property> > > <property> > <name>dfs.replication</name> > <value>2</value> > </property> > </configuration> > > SLAVE > > 1) conf/slaves > localhost > > 2) conf/master > [EMAIL PROTECTED] > > 3) conf/hadoop-site.xml > <?xml version="1.0"?> > <?xml-stylesheet type="text/xsl" href="configuration.xsl"?> > > <!-- Put site-specific property overrides in this file. --> > > <configuration> > <property> > <name>fs.default.name</name> > <value>192.168.1.150:50000</value> > </property> > > <property> > <name>mapred.job.tracker</name> > <value>192.168.1.150:50001</value> > </property> > > <property> > <name>dfs.replication</name> > <value>2</value> > </property> > </configuration> > > > CONSOLE OUTPUT > bin/hadoop jar hadoop-*-examples.jar wordcount -m 10 -r 2 input output > 07/03/06 23:17:17 INFO mapred.InputFormatBase: Total input paths to > process : 1 > 07/03/06 23:17:18 INFO mapred.JobClient: Running job: job_0001 > 07/03/06 23:17:19 INFO mapred.JobClient: map 0% reduce 0% > 07/03/06 23:17:29 INFO mapred.JobClient: map 20% reduce 0% > 07/03/06 23:17:30 INFO mapred.JobClient: map 40% reduce 0% > 07/03/06 23:17:32 INFO mapred.JobClient: map 80% reduce 0% > 07/03/06 23:17:33 INFO mapred.JobClient: map 100% reduce 0% > 07/03/06 23:17:42 INFO mapred.JobClient: map 100% reduce 3% > 07/03/06 23:17:43 INFO mapred.JobClient: map 100% reduce 5% > 07/03/06 23:17:44 INFO mapred.JobClient: map 100% reduce 8% > 07/03/06 23:17:52 INFO mapred.JobClient: map 100% reduce 10% > 07/03/06 23:17:53 INFO mapred.JobClient: map 100% reduce 13% > 07/03/06 23:18:03 INFO mapred.JobClient: map 100% reduce 16% > > > The only exception I can see from the log files is in the 'TaskTracker' > log file: > > 2007-03-06 23:17:32,214 INFO org.apache.hadoop.mapred.TaskRunner: > task_0001_r_000000_0 Copying task_0001_m_000002_0 output from traal. > 2007-03-06 23:17:32,221 INFO org.apache.hadoop.mapred.TaskRunner: > task_0001_r_000000_0 Copying task_0001_m_000001_0 output from > dennis-laptop. > 2007-03-06 23:17:32,368 WARN org.apache.hadoop.mapred.TaskRunner: > task_0001_r_000000_0 copy failed: task_0001_m_000002_0 from traal > 2007-03-06 23:17:32,368 WARN org.apache.hadoop.mapred.TaskRunner: > java.io.IOException: File > /tmp/hadoop-hadoop/mapred/local/task_0001_r_000000_0/map_2.out-0 not > created > at > org.apache.hadoop.mapred.ReduceTaskRunner$MapOutputCopier.copyOutput(ReduceTaskRunner.java:301) > at > org.apache.hadoop.mapred.ReduceTaskRunner$MapOutputCopier.run(ReduceTaskRunner.java:262) > > 2007-03-06 23:17:32,369 WARN org.apache.hadoop.mapred.TaskRunner: > task_0001_r_000000_0 adding host traal to penalty box, next contact in 99 > seconds > > I am attaching the master log files just in case anyone wants to check > them. > > Any help will be greatly appreciated! > > -gaurav > > > http://www.nabble.com/file/7013/hadoop-hadoop-tasktracker-dennis-laptop.log > hadoop-hadoop-tasktracker-dennis-laptop.log </br> > http://www.nabble.com/file/7012/hadoop-hadoop-jobtracker-dennis-laptop.log > hadoop-hadoop-jobtracker-dennis-laptop.log </br> > http://www.nabble.com/file/7011/hadoop-hadoop-namenode-dennis-laptop.log > hadoop-hadoop-namenode-dennis-laptop.log </br> > http://www.nabble.com/file/7010/hadoop-hadoop-datanode-dennis-laptop.log > hadoop-hadoop-datanode-dennis-laptop.log > -- View this message in context: http://www.nabble.com/Hadoop-%27wordcount%27-program-hanging-in-the-Reduce-phase.-tf3360661.html#a9369365 Sent from the Hadoop Users mailing list archive at Nabble.com.
