Dear Zhou, With Hadoop-0.20.2, you need to use JDK1.6. If you have a newer version of Java, it will be the problem. You can also use newer hadoop versions with newer JDK.
Regards, Nooshin On Thu, Dec 10, 2015 at 2:26 PM, 周子博 <15120...@bjtu.edu.cn> wrote: > Hello > I'm studying Hadoop these days. When I finished install hadoop under > Fedora 19, I try to run wordcount but I can't. > The error in userlogs as follow:(/logs/userlogs/attemp.../syslog) > > 2015-12-10 19:42:52,276 INFO org.apache.hadoop.metrics.jvm.JvmMetrics: > Initializing JVM Metrics with processName=MAP, sessionId= > 2015-12-10 19:42:52,427 WARN org.apache.hadoop.mapred.TaskTracker: Error > running child > java.lang.ClassCastException: org.apache.hadoop.mapreduce.lib.input.FileSplit > cannot be cast to org.apache.hadoop.mapred.InputSplit > at org.apache.hadoop.mapred.MapTask.runOldMapper(MapTask.java:323) > at org.apache.hadoop.mapred.MapTask.run(MapTask.java:307) > at org.apache.hadoop.mapred.Child.main(Child.java:170) > 2015-12-10 19:42:52,432 INFO org.apache.hadoop.mapred.TaskRunner: Runnning > cleanup for the task > > I think the problem is the mapred and mapreduce cannot be matched.(Is it > right?) > I tried to find out the solution on the Internet. But all I find are > telling about the difference between the mapred and mapreduce, but I still > don't know how to fix the program. > Hope I can get the answer. > Thank you very very much. > > Yours, > Zhou > > Sorry,I forgot to say my hadoop version is hadoop-0.20.2 . Should I try to > install version hadoop-1.x or higher? >
