I am experimenting on a small cluster as well (4 machines) and I had success with the following configuration:
- configuration files on both the master and slaves are the same - in the master/slave lists I only used the ip address (not localhost) and ommited the user e.g. (hadoop@) - in the fs.default.name configuration variable use hdfs://<host>:<port> (I don't know if this is necessary - but it seems you can specify other types of filesystems - not sure which is default) - use 0.12.0 release - I was using 0.11.2 and was getting some odd errors that disappeared when I upgraded - I don't run a datanode daemon on the same machine a the namenode -- this was a problem when I was trying the hadoop-streaming contributed package for scripting. Not sure if it matters for the examples This configuration worked me. -Brian On 3/7/07, Gaurav Agarwal <[EMAIL PROTECTED]> wrote:
Hi Richard, I am facing this error very consistently. I have tried the another nightly build (4 Mar) but that gave same exception. thanks, gaurav Richard Yang-3 wrote: > > Hi Gaurav, > > Does this error always happen?? > Our settings are similar. > Mine contains some error messages about IOExceptions, not able to obtain > certain blocks, not able to create a new block. Although the program hung > some time, in most cases, they were able to complete with correct results. > Btw, I am running the grep sample program on version 0.11.2. > > Best Regards > > Richard Yang > [EMAIL PROTECTED] > [EMAIL PROTECTED] > > > -----Original Message----- > From: Gaurav Agarwal [mailto:[EMAIL PROTECTED] > Sent: Wednesday, March 07, 2007 12:22 AM > To: [email protected] > Subject: Hadoop 'wordcount' program hanging in the Reduce phase. > > > Hi Everyone! > I am new user to Hadoop and trying to set up a small cluster using Hadoop. > 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$MapOutputCopier.copyOutput(ReduceT > askRunner.java:301) > at > org.apache.hadoop.mapred.ReduceTaskRunner$MapOutputCopier.run(ReduceTaskRunn > er.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-p > hase.-tf3360661.html#a9348424 > Sent from the Hadoop Users mailing list archive at Nabble.com. > > > > > -- View this message in context: http://www.nabble.com/Hadoop-%27wordcount%27-program-hanging-in-the-Reduce-phase.-tf3360661.html#a9357648 Sent from the Hadoop Users mailing list archive at Nabble.com.
