提交wordcount mapreduce作业报错

[雪____]

hadoop和zookeeper都正常启动
提交wordcount作业
报错： mapreduce.Job: Job job_1494139132239_0001 failed with state FAILED due to: Application application_1494139132239_0001 failed 2 times due to Error launching appattempt_1494139132239_0001_000002. Got exception: java.net.ConnectException: Call From master.localdomain/127.0.0.1 to localhost:38542 failed on connection exception: java.net.ConnectException: Connection refused; For more details see: http://wiki.apache.org/hadoop/ConnectionRefused
我的mapred-site如下：
<configuration>
<property>
<name>mapreduce.framework.name</name>
<value>yarn</value>
</property>
<property>
<name>mapreduce.jobtracker.address</name>
<value>master:9001</value>
</property>
<property>
<name>mapreduce.jobhistory.address</name>
<value>master:10020</value>
</property>
<property>
<name>mapreduce.jobhistory.webapp.address</name>
<value>master:19888</value>
</property>

[雪____]

本人已解决，是因为hostname的问题，去找那几个hostname有关的文件就好