Enabling Log Aggregation in YARN

While checking the details of a YARN applications, if you are getting a message similar to “Log Aggregation not enabled”. You can follow the below steps to enable it. This issue occurs in EMR, because in most of the AMI’s the log aggregation is not enabled by default. It is very simple to enable it. Add the following configuration to the yarn-site.xml of all the yarn hosts and restart the cluster. (full cluster restart is not required. Restarting all the nodemanagers will be fine)

<property>
    <name>yarn.log-aggregation-enable</name>
    <value>true</value>
</property>

<property>
    <description>Where to aggregate logs to.</description>
    <name>yarn.nodemanager.remote-app-log-dir</name>
    <value>/tmp/logs</value>
</property>

<property>
    <name>yarn.log-aggregation.retain-seconds</name>
    <value>259200</value>
</property>

<property>
    <name>yarn.log-aggregation.retain-check-interval-seconds</name>
    <value>3600</value>
</property>