yarn启动报错：
2016-11-16 16:12:44,304 INFO org.apache.hadoop.metrics2.impl.MetricsSystemImpl: Stopping NodeManager metrics system...
2016-11-16 16:12:44,304 INFO org.apache.hadoop.metrics2.impl.MetricsSystemImpl: NodeManager metrics system stopped.
2016-11-16 16:12:44,304 INFO org.apache.hadoop.metrics2.impl.MetricsSystemImpl: NodeManager metrics system shutdown complete.
2016-11-16 16:12:44,305 FATAL org.apache.hadoop.yarn.server.nodemanager.NodeManager: Error starting NodeManager
org.apache.hadoop.yarn.exceptions.YarnRuntimeException: java.net.ConnectException: Call From node02/172.16.145.112 to 0.0.0.0:8031 failed on connection exception: java.net.ConnectException: Connection refused; For more details see: http://wiki.apache.org/hadoop/ConnectionRefused
at org.apache.hadoop.yarn.server.nodemanager.NodeStatusUpdaterImpl.serviceStart(NodeStatusUpdaterImpl.java:198)
at org.apache.hadoop.service.AbstractService.start(AbstractService.java:193)
at org.apache.hadoop.service.CompositeService.serviceStart(CompositeService.java:120)
at org.apache.hadoop.yarn.server.nodemanager.NodeManager.serviceStart(NodeManager.java:264)
at org.apache.hadoop.service.AbstractService.start(AbstractService.java:193)
at org.apache.hadoop.yarn.server.nodemanager.NodeManager.initAndStartNodeManager(NodeManager.java:463)
at org.apache.hadoop.yarn.server.nodemanager.NodeManager.main(NodeManager.java:509)
Caused by: java.net.ConnectException: Call From node02/172.16.145.112 to 0.0.0.0:8031 failed on connection exception: java.net.ConnectException: Connection refused; For more details see: http://wiki.apache.org/hadoop/ConnectionRefused
at sun.reflect.GeneratedConstructorAccessor7.newInstance(Unknown Source)
at sun.reflect.DelegatingConstructorAccessorImpl.newInstance(DelegatingConstructorAccessorImpl.java:45)
at java.lang.reflect.Constructor.newInstance(Constructor.java:526)
at org.apache.hadoop.net.NetUtils.wrapWithMessage(NetUtils.java:783)
at org.apache.hadoop.net.NetUtils.wrapException(NetUtils.java:730)
at org.apache.hadoop.ipc.Client.call(Client.java:1415)
at org.apache.hadoop.ipc.Client.call(Client.java:1364)
at org.apache.hadoop.ipc.ProtobufRpcEngine$Invoker.invoke(ProtobufRpcEngine.java:206)
at com.sun.proxy.$Proxy27.registerNodeManager(Unknown Source)
at org.apache.hadoop.yarn.server.api.impl.pb.client.ResourceTrackerPBClientImpl.registerNodeManager(ResourceTrackerPBClientImpl.java:68)
at sun.reflect.GeneratedMethodAccessor2.invoke(Unknown Source)
at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
at java.lang.reflect.Method.invoke(Method.java:606)
at org.apache.hadoop.io.retry.RetryInvocationHandler.invokeMethod(RetryInvocationHandler.java:187)
at org.apache.hadoop.io.retry.RetryInvocationHandler.invoke(RetryInvocationHandler.java:102)
at com.sun.proxy.$Proxy28.registerNodeManager(Unknown Source)
at org.apache.hadoop.yarn.server.nodemanager.NodeStatusUpdaterImpl.registerWithRM(NodeStatusUpdaterImpl.java:258)
at org.apache.hadoop.yarn.server.nodemanager.NodeStatusUpdaterImpl.serviceStart(NodeStatusUpdaterImpl.java:192)
... 6 more
Caused by: java.net.ConnectException: Connection refused
at sun.nio.ch.SocketChannelImpl.checkConnect(Native Method)
at sun.nio.ch.SocketChannelImpl.finishConnect(SocketChannelImpl.java:739)
at org.apache.hadoop.net.SocketIOWithTimeout.connect(SocketIOWithTimeout.java:206)
at org.apache.hadoop.net.NetUtils.connect(NetUtils.java:529)
at org.apache.hadoop.net.NetUtils.connect(NetUtils.java:493)
at org.apache.hadoop.ipc.Client$Connection.setupConnection(Client.java:606)
at org.apache.hadoop.ipc.Client$Connection.setupIOstreams(Client.java:700)
错误原因：8031端口是yarn.resourcemanager.resource-tracker.address的默认端口，yarn-site中没有配置这个的地址，nodemanager会默认去连接
0.0.0.0:8031
yarn.resourcemanager.resource-tracker.address
参数解释：ResourceManager 对NodeManager暴露的地址.。NodeManager通过该地址向RM汇报心跳，领取任务等。
默认值：${yarn.resourcemanager.hostname}:8031
解决办法：修改yarn-site.xml 增加如下设置
<property>
<name>yarn.resourcemanager.resource-tracker.address.rm1</name>
<value>node04:8031</value>
</property>
<property>
<name>yarn.resourcemanager.resource-tracker.address.rm2</name>
<value>node05:8031</value>
</property>