configuration for mapreduce.framework.name and the correspond server addresses.

今天安装调试hadoop2.5.2 的时候运行wordcount例子，报错如下：
[root@Master sbin]# hadoop jar /usr/local/hadoop/share/hadoop/mapreduce/hadoop-mapreduce-examples-2.5.2.jar wordcount /input /output
15/05/12 13:50:12 WARN util.NativeCodeLoader: Unable to load native-hadoop library for your platform... using builtin-java classes where applicable
java.io.IOException: Cannot initialize Cluster. Please check your configuration for mapreduce.framework.name and the correspond server addresses.
        at org.apache.hadoop.mapreduce.Cluster.initialize(Cluster.java:120)
        at org.apache.hadoop.mapreduce.Cluster.(Cluster.java:82)
        at org.apache.hadoop.mapreduce.Cluster.(Cluster.java:75)
        at org.apache.hadoop.mapreduce.Job$9.run(Job.java:1255)
        at org.apache.hadoop.mapreduce.Job$9.run(Job.java:1251)
        at java.security.AccessController.doPrivileged(Native Method)
        at javax.security.auth.Subject.doAs(Subject.java:422)
        at org.apache.hadoop.security.UserGroupInformation.doAs(UserGroupInformation.java:1614)
        at org.apache.hadoop.mapreduce.Job.connect(Job.java:1250)
        at org.apache.hadoop.mapreduce.Job.submit(Job.java:1279)
        at org.apache.hadoop.mapreduce.Job.waitForCompletion(Job.java:1303)
        at org.apache.hadoop.examples.WordCount.main(WordCount.java:87)
        at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
        at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:62)
        at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
        at java.lang.reflect.Method.invoke(Method.java:497)
        at org.apache.hadoop.util.ProgramDriver$ProgramDescription.invoke(ProgramDriver.java:72)
        at org.apache.hadoop.util.ProgramDriver.run(ProgramDriver.java:145)
        at org.apache.hadoop.examples.ExampleDriver.main(ExampleDriver.java:74)
        at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
        at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:62)
        at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
        at java.lang.reflect.Method.invoke(Method.java:497)
        at org.apache.hadoop.util.RunJar.main(RunJar.java:212)


肯定是配置问题，在网上又搜搜其他的配置文档，
最后发现mapred-site.xml文件中

mapreduce.framework.name
Yarn（错误写法Yarn，大小写问题，需要改成yarn）


重新启动yarn，运行wordcount成功。