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Posted to mapreduce-user@hadoop.apache.org by Jane Chen <jx...@yahoo.com> on 2011/03/16 22:29:00 UTC
TaskTracker failed to start: NoClassDefFoundError: Configured.
Hi,
I was trying to start up a single-node Hadoop cluster using 0.20.2.
The namenode, datanode and jobtracker all started fine. The task tracker failed with the following error:
2011-03-16 11:39:47,479 INFO org.apache.hadoop.mapred.TaskTracker: Starting thread: Map-events fetcher for all reduce tasks on tracker_localhost:localhost/127.0.0.1:58447
2011-03-16 11:39:47,480 ERROR org.apache.hadoop.mapred.TaskTracker: Can not start task tracker because java.lang.NoClassDefFoundError: Configured
at java.lang.ClassLoader.defineClass1(Native Method)
at java.lang.ClassLoader.defineClassCond(ClassLoader.java:632)
at java.lang.ClassLoader.defineClass(ClassLoader.java:616)
at java.security.SecureClassLoader.defineClass(SecureClassLoader.java:141)
at java.net.URLClassLoader.defineClass(URLClassLoader.java:283)
at java.net.URLClassLoader.access$000(URLClassLoader.java:58)
at java.net.URLClassLoader$1.run(URLClassLoader.java:197)
at java.security.AccessController.doPrivileged(Native Method)
at java.net.URLClassLoader.findClass(URLClassLoader.java:190)
at java.lang.ClassLoader.loadClass(ClassLoader.java:307)
at sun.misc.Launcher$AppClassLoader.loadClass(Launcher.java:301)
at java.lang.ClassLoader.loadClass(ClassLoader.java:248)
at java.lang.ClassLoader.defineClass1(Native Method)
at java.lang.ClassLoader.defineClassCond(ClassLoader.java:632)
at java.lang.ClassLoader.defineClass(ClassLoader.java:616)
at java.security.SecureClassLoader.defineClass(SecureClassLoader.java:141)
The HADOOP_CLASSPATH is set in hadoop-env.sh. The classpath includes hadoop-0.20.2-core.jar, which contains Configured. Any clues?
Thanks,
Jane