hadoop conf

Examples

Displaying the configured value of a specific parameter

[user@hostname ~]$ hadoop conf | grep mapreduce.map.memory.mb
<property><name>mapreduce.map.memory.mb</name><value>1024</value><source>mapred-site.xml</source></property>

The above command returns 1024 as the configured value of the mapreduce.map.memory.mb parameter.

Dumping a node's configuration to a text file

[user@hostname ~]$ hadoop conf | grep ... >nodeconfiguration.txt  

The above command creates a text file named nodeconfiguration.txt that contains the node's configuration information.

The following information displays when you use the tail utility to examine the last few lines of the file:

[user@hostname ~]# tail nodeconfiguration.txt
            <property><name>yarn.app.mapreduce.am.resource.mb</name><value>1536</value><source>mapred-default.xml</source></property>
            <property><name>mapreduce.framework.name</name><value>yarn</value><source>mapred-default.xml</source></property>
            <property><name>mapreduce.job.reduce.slowstart.completedmaps</name><value>1.00</value><source>mapred-default.xml</source></property>
            <property><name>yarn.resourcemanager.client.thread-count</name><value>50</value><source>yarn-default.xml</source></property>
            <property><name>mapreduce.cluster.temp.dir</name><value>${hadoop.tmp.dir}/mapred/temp</value><source>mapred-default.xml</source></property>
            <property><name>yarn.resourcemanager.staging</name><value>/var/mapr/cluster/yarn/rm/staging</value></property>
            <property><name>fs.mapr.working.dir</name><value>/user/$USERNAME/</value></property>
            <property><name>mapreduce.jobhistory.intermediate-done-dir</name><value>${yarn.app.mapreduce.am.staging-dir}/history/done_intermediate</value><source>mapred-default.xml</source></property>
            <property><name>fs.s3a.attempts.maximum</name><value>10</value><source>core-default.xml</source></property>
            </configuration>