mapred.child.java.opts are referring to the settings for the JVMs spawned by the TaskTracker. This JVMs will actually run the tasks (mappers and reducers)
The heap sizes for TaskTrackers and DataNodes are unrelated to those. They run in their own JVMs each. Kai Am 25.11.2013 um 15:52 schrieb Chih-Hsien Wu <[email protected]>: > I'm learning about Hadoop configuration. What is the connection between the > datanode/ tasktracker heap sizes and the "mapre.child.java.opts"? Does one > have to be exceeded to another? Kai Voigt Am Germaniahafen 1 [email protected] 24143 Kiel +49 160 96683050 Germany @KaiVoigt
