I have a cluster of 4 machines with 24 cores and 7 disks each.
On each node I copied from local a file of 500G. So I have 4 files in hdfs with
many blocks. My replication factor is 1.
I run a job (a scalding flow) and while there are 96 reducers pending, there
are only 4 active map tasks.
What am I doing wrong? Below is the configuration
Thanks,
Ittay
<configuration>
<property>
<name>mapred.job.tracker</name>
<value>master:54311</value>
</property>
<property>
<name>mapred.map.tasks</name>
<value>96</value>
</property>
<property>
<name>mapred.reduce.tasks</name>
<value>96</value>
</property>
<property>
<name>mapred.local.dir</name>
<value>/hdfs/0/mapred/local,/hdfs/1/mapred/local,/hdfs/2/mapred/local,/hdfs/3/mapred/local,/hdfs/4/mapred/local,/hdfs/5/mapred/local,/hdfs/6/mapred/local,/hdfs/7/mapred/local</value>
</property>
<property>
<name>mapred.tasktracker.map.tasks.maximum</name>
<value>24</value>
</property>
<property>
<name>mapred.tasktracker.reduce.tasks.maximum</name>
<value>24</value>
</property>
</configuration>
