Help Center/ MapReduce Service/ Developer Guide (Normal_3.x)/ Oozie Development Guide (Normal Mode)/ Developing the Project/ Example Codes/ MapReduce Action
Updated on 2022-09-14 GMT+08:00
View PDF

MapReduce Action

Function

The MapReduce Action node is used to execute a map-reduce job.

Parameter Description

Table 1 describes parameters used on the MapReduce Action node.

Table 1 Parameters

Parameter

Meaning

name

Identifies a map-reduce action.

resourceManager

Indicates the MapReduce ResourceManager address.

name-node

Indicates the Hadoop distributed file system (HDFS) NameNode address.

queueName

Identifies the MapReduce queue where a job is executed.

mapred.mapper.class

Identifies the Mapper class.

mapred.reducer.class

Identifies the Reducer class.

mapred.input.dir

Indicates the input directory of MapReduce processed data.

mapred.output.dir

Indicates the output directory of MapReduce processing results.

mapred.map.tasks

Indicates the number of map tasks.

${variable name} indicates the value defined in job.properties.

For example, ${nameNode} indicates hdfs://hacluster. (See job.properties.)

Example Codes

Change OOZIE_URL_DEFALUT in the code example to the actual host name of any Oozie node, for example, https://10-1-131-131:21003/oozie/.

<action name="mr-dataLoad">
     <map-reduce>
          <resource-manager>${resourceManager}</resource-manager>
          <name-node>${nameNode}</name-node>
          <prepare>
              <delete path="${nameNode}/user/${wf:user()}/${dataLoadRoot}/output-data/map-reduce"/>
          </prepare>
          <configuration>
              <property>
                  <name>mapred.job.queue.name</name>
                  <value>${queueName}</value>
              </property>
              <property>
                  <name>mapred.mapper.class</name>
                  <value>org.apache.oozie.example.SampleMapper</value>
              </property>
              <property>
                  <name>mapred.reducer.class</name>
                  <value>org.apache.oozie.example.SampleReducer</value>
              </property>
              <property>
                  <name>mapred.map.tasks</name>
                  <value>1</value>
              </property>
              <property>
                  <name>mapred.input.dir</name>
                  <value>/user/oozie/${dataLoadRoot}/input-data/text</value>
                </property>
                <property>
                    <name>mapred.output.dir</name>
                    <value>/user/${wf:user()}/${dataLoadRoot}/output-data/map-reduce</value>
                </property>
            </configuration>
        </map-reduce>
        <ok to="copyData"/>
        <error to="fail"/>
    </action>
Parent topic: Example Codes