hadoop - Oozie > Java action > why property oozie.launcher.mapred.child.java.opts does not work

Question

I am working on Oozie with a Java action. The Java action should use Java option -Xmx15g. Accordingly I set the property oozie.mapreduce.map.memory.mb to 25600 (25G) in case some extra memory is needed.

After this simple setting, I ran the Oozie job, then there was of course OutofMemory (heap out of space) error during Java runtime.

So I set oozie.launcher.mapred.child.java.opts as -Xmx15g accordingly in the property node of the Java action based on the link: http://downright-amazed.blogspot.fi/2012/02/configure-oozies-launcher-job.html. But I still got the same OutofMemory error. Then I tried to add -Xmx15g to the node java-opts inside the Java action node. This worked fine, but if so whats the hell there is still the property oozie.launcher.mapred.child.java.opts?

Anyone has any idea why it is like that? Please given some comments on why it is like that. Thanks in advance.

I really feel that Oozie is not a handy tool.

Answer 1

I am not sure what "task" means in mapred.child.java.opts

Try mapreduce.map.java.opts instead, as in this example:

<configuration>
    <property>
      <name>oozie.launcher.mapreduce.map.memory.mb</name>
      <value>16384</value>
    </property>
    <property>
      <name>oozie.launcher.mapreduce.map.java.opts</name>
      <value>-Xmx15g</value>
    </property>
    <property>
      <name>oozie.launcher.yarn.app.mapreduce.am.resource.mb</name>
      <value>768</value>
    </property>
    <property>
      <name>oozie.launcher.yarn.app.mapreduce.am.command-opts</name>
      <value>-Xmx512m</value>
    </property>
    <property>
      <name>oozie.launcher.mapred.job.queue.name</name>
      <value>default</value>
    </property>
</configuration>