These properties are not available on Apache Hadoop 1.0 (Formerly known as 0.20.x). This was a feature introduced in 0.21 (https://issues.apache.org/jira/browse/MAPREDUCE-478), and is available today on 0.22 and 0.23 line of releases.
For 1.0/0.20, use "mapred.child.java.opts", that applies to both map and reduce commonly. Would also be helpful if you can tell us what doc guided you to use these property names instead of the proper one, so we can fix it. On Thu, Jan 12, 2012 at 8:44 AM, T Vinod Gupta <[email protected]> wrote: > Hi, > Can someone help me asap? when i run my mapred job, it fails with this > error - > 12/01/12 02:58:36 INFO mapred.JobClient: Task Id : > attempt_201112151554_0050_m_000071_0, Status : FAILED > Error: Java heap space > attempt_201112151554_0050_m_000071_0: log4j:ERROR Failed to flush writer, > attempt_201112151554_0050_m_000071_0: java.io.IOException: Stream closed > attempt_201112151554_0050_m_000071_0: at > sun.nio.cs.StreamEncoder.ensureOpen(StreamEncoder.java:44) > attempt_201112151554_0050_m_000071_0: at > sun.nio.cs.StreamEncoder.flush(StreamEncoder.java:139) > attempt_201112151554_0050_m_000071_0: at > java.io.OutputStreamWriter.flush(OutputStreamWriter.java:229) > attempt_201112151554_0050_m_000071_0: at > org.apache.log4j.helpers.QuietWriter.flush(QuietWriter.java:58) > attempt_201112151554_0050_m_000071_0: at > org.apache.hadoop.mapred.TaskLogAppender.flush(TaskLogAppender.java:94) > attempt_201112151554_0050_m_000071_0: at > org.apache.hadoop.mapred.TaskLog.syncLogs(TaskLog.java:260) > attempt_201112151554_0050_m_000071_0: at > org.apache.hadoop.mapred.Child$2.run(Child.java:142) > > > so i updated my mapred-site.xml with these settings - > > <property> > <name>mapred.map.child.java.opts</name> > <value>-Xmx2048M</value> > </property> > > <property> > <name>mapred.reduce.child.java.opts</name> > <value>-Xmx2048M</value> > </property> > > also, when i run my jar, i provide - > "-Dmapred.map.child.java.opts="-Xmx4000m" at the end. > inspite of this, the task is not getting the max heap size im setting. > > where did i go wrong? > > after changing mapred-site.xml, i restarted jobtracker and tasktracker.. is > that not good enough? > > thanks -- Harsh J
