title: Oozie > Java action > why property oozie.launcher.mapred.child.java.opts does not work
body: <p>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. </p>
  
  <p>After this simple setting, I ran the Oozie job, then there was of course OutofMemory (heap out of space) error during Java runtime. </p>
  
  <p>So I set oozie.launcher.mapred.child.java.opts as -Xmx15g accordingly in the property node of the Java action based on the link: <a href="http://downright-amazed.blogspot.fi/2012/02/configure-oozies-launcher-job.html" rel="nofollow">http://downright-amazed.blogspot.fi/2012/02/configure-oozies-launcher-job.html</a>. 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? </p>
  
  <p>Anyone has any idea why it is like that? Please given some comments on why it is like that. Thanks in advance.</p>
  
  <p>I really feel that Oozie is not a handy tool.</p>