hadoop: having more than one reducers under pseudo distributed environment? - hadoop

Question

I am newbie to hadoop. I have successfully configured a hadoop setup in pseudo distributed mode. I want to have multiple reducers with the option -D mapred.reduce.tasks=2 (with hadoop-streaming). however there's still only one reducer.
according to Google I'm sure that mapred.LocalJobRunner limits number of reducers to 1. But I wonder is there any workaround to have more reducers?
my hadoop configuration files:
[admin#localhost string-count-hadoop]$ cat ~/hadoop-1.1.2/conf/core-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>hdfs://localhost:9000</value>
</property>
<property>
<name>hadoop.tmp.dir</name>
<value>/home/admin/hadoop-data/tmp</value>
</property>
</configuration>
[admin#localhost string-count-hadoop]$ cat ~/hadoop-1.1.2/conf/mapred-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>mapred.job.tracker</name>
<value>localhost:9001</value>
</property>
</configuration>
[admin#localhost string-count-hadoop]$ cat ~/hadoop-1.1.2/conf/hdfs-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>dfs.name.dir</name>
<value>/home/admin/hadoop-data/name</value>
</property>
<property>
<name>dfs.data.dir</name>
<value>/home/admin/hadoop-data/data</value>
</property>
<property>
<name>dfs.replication</name>
<value>1</value>
</property>
</configuration>
the way I start job:
[admin#localhost string-count-hadoop]$ cat hadoop-startjob.sh
#!/bin/sh
~/hadoop-1.1.2/bin/hadoop jar ~/hadoop-1.1.2/contrib/streaming/hadoop-streaming-1.1.2.jar \
-D mapred.job.name=string-count \
-D mapred.reduce.tasks=2 \
-mapper mapper \
-file mapper \
-reducer reducer \
-file reducer \
-input $1 \
-output $2
[admin#localhost string-count-hadoop]$ ./hadoop-startjob.sh /z/programming/testdata/items_sequence /z/output
packageJobJar: [mapper, reducer] [] /tmp/streamjob837249979139287589.jar tmpDir=null
13/07/17 20:21:10 INFO util.NativeCodeLoader: Loaded the native-hadoop library
13/07/17 20:21:10 WARN snappy.LoadSnappy: Snappy native library not loaded
13/07/17 20:21:10 INFO mapred.FileInputFormat: Total input paths to process : 1
13/07/17 20:21:11 WARN mapred.LocalJobRunner: LocalJobRunner does not support symlinking into current working dir.
...
...

Answer 1

Try modifying core-site.xml's property
<property>
<name>fs.default.name</name>
<value>hdfs://localhost:9000</value>
</property>
to,
<property>
<name>fs.default.name</name>
<value>hdfs://localhost:9000/</value>
</property>
Put an extra / after 9000 and restart all the daemons.