MapReduce in Hadoop 2.2.0 not working

Question

After installing and configuring my Hadoop 2.2.0 in pseudo-distributed mode everything is running, as you can see in the jps:

$ jps         


        

Answer 1

The problem was in the file yarn-site.xml. The property must be larger than 3072 Mb, and I had it configured to 1024 Mb, so the correct way is

<property>
    <name>yarn.nodemanager.resource.memory-mb</name>
    <value>4096</value>
    <description>Physical memory, in MB, to be made available to running containers</description>
</property>

Answer 2

I think the log is not detailed enough，you can first Open the debug mode：

export HADOOP_ROOT_LOGGER=DEBUG,console

then run wordcount job for see more log and paste