mapreduce程序无法运行，困扰了好久，求各位大佬帮忙，感激不尽

[_zhqy]

我在5台服务器上搭建了个hadoop集群，无论是运行自己写的程序还是运行MapReduce的示例程序PI，都无法执行，运行结果都是这样：
18/06/04 16:00:23 INFO mapreduce.Job: Running job: job_1528028379845_0006
18/06/04 16:01:05 INFO mapreduce.Job: Job job_1528028379845_0006 running in uber mode : false
18/06/04 16:01:05 INFO mapreduce.Job: map 0% reduce 0%
18/06/04 16:01:06 INFO mapreduce.Job: Job job_1528028379845_0006 failed with state FAILED due to: Application application_1528028379845_0006 failed 2 times due to AM Container for appattempt_1528028379845_0006_000002 exited with exitCode: 1
查看Container的日志，看到这样一些信息：
2018-06-04 16:00:58,564 ERROR [main] org.apache.hadoop.mapreduce.v2.app.client.MRClientService: Webapps failed to start. Ignoring for now:
java.lang.NullPointerException
at org.apache.hadoop.util.StringUtils.join(StringUtils.java:930)
at org.apache.hadoop.yarn.server.webproxy.amfilter.AmFilterInitializer.initFilter(AmFilterInitializer.java:75)
at org.apache.hadoop.http.HttpServer2.initializeWebServer(HttpServer2.java:466)
at org.apache.hadoop.http.HttpServer2.<init>(HttpServer2.java:412)
at org.apache.hadoop.http.HttpServer2.<init>(HttpServer2.java:115)
at org.apache.hadoop.http.HttpServer2$Builder.build(HttpServer2.java:336)
at org.apache.hadoop.yarn.webapp.WebApps$Builder.build(WebApps.java:315)
at org.apache.hadoop.yarn.webapp.WebApps$Builder.start(WebApps.java:401)
at org.apache.hadoop.yarn.webapp.WebApps$Builder.start(WebApps.java:397)
at org.apache.hadoop.mapreduce.v2.app.client.MRClientService.serviceStart(MRClientService.java:143)
at org.apache.hadoop.service.AbstractService.start(AbstractService.java:194)
at org.apache.hadoop.mapreduce.v2.app.MRAppMaster.serviceStart(MRAppMaster.java:1269)
...
at org.apache.hadoop.mapreduce.v2.app.MRAppMaster.initAndStartAppMaster(MRAppMaster.java:1719)
at org.apache.hadoop.mapreduce.v2.app.MRAppMaster.main(MRAppMaster.java:1650)
2018-06-04 16:00:58,705 ERROR [main] org.apache.hadoop.mapreduce.v2.app.rm.RMCommunicator: Exception while registering
java.lang.NullPointerException
at org.apache.hadoop.mapreduce.v2.app.client.MRClientService.getHttpPort(MRClientService.java:177)
at org.apache.hadoop.mapreduce.v2.app.rm.RMCommunicator.register(RMCommunicator.java:156)
at org.apache.hadoop.mapreduce.v2.app.rm.RMCommunicator.serviceStart(RMCommunicator.java:121)
at org.apache.hadoop.mapreduce.v2.app.rm.RMContainerAllocator.serviceStart(RMContainerAllocator.java:274)
at org.apache.hadoop.service.AbstractService.start(AbstractService.java:194)
at org.apache.hadoop.mapreduce.v2.app.MRAppMaster$ContainerAllocatorRouter.serviceStart(MRAppMaster.java:959)
at org.apache.hadoop.service.AbstractService.start(AbstractService.java:194)
at org.apache.hadoop.service.CompositeService.serviceStart(CompositeService.java:121)
at org.apache.hadoop.mapreduce.v2.app.MRAppMaster.serviceStart(MRAppMaster.java:1272)
...
at org.apache.hadoop.mapreduce.v2.app.MRAppMaster.initAndStartAppMaster(MRAppMaster.java:1719)
at org.apache.hadoop.mapreduce.v2.app.MRAppMaster.main(MRAppMaster.java:1650)
2018-06-04 16:00:58,706 INFO [main] org.apache.hadoop.service.AbstractService: Service RMCommunicator failed in state STARTED; cause: org.apache.hadoop.yarn.exceptions.YarnRuntimeException: java.lang.NullPointerException
org.apache.hadoop.yarn.exceptions.YarnRuntimeException: java.lang.NullPointerException
at org.apache.hadoop.mapreduce.v2.app.rm.RMCommunicator.register(RMCommunicator.java:177)
at org.apache.hadoop.mapreduce.v2.app.rm.RMCommunicator.serviceStart(RMCommunicator.java:121)
at org.apache.hadoop.mapreduce.v2.app.rm.RMContainerAllocator.serviceStart(RMContainerAllocator.java:274)
at org.apache.hadoop.service.AbstractService.start(AbstractService.java:194)
at org.apache.hadoop.mapreduce.v2.app.MRAppMaster$ContainerAllocatorRouter.serviceStart(MRAppMaster.java:959)
at org.apache.hadoop.service.AbstractService.start(AbstractService.java:194)
at org.apache.hadoop.service.CompositeService.serviceStart(CompositeService.java:121)
at org.apache.hadoop.mapreduce.v2.app.MRAppMaster.serviceStart(MRAppMaster.java:1272)
...
Caused by: java.lang.NullPointerException
at org.apache.hadoop.mapreduce.v2.app.client.MRClientService.getHttpPort(MRClientService.java:177)
at org.apache.hadoop.mapreduce.v2.app.rm.RMCommunicator.register(RMCommunicator.java:156)
... 14 more

2018-06-04 16:00:58,707 INFO [main] org.apache.hadoop.service.AbstractService: Service org.apache.hadoop.mapreduce.v2.app.MRAppMaster$ContainerAllocatorRouter failed in state STARTED; cause: org.apache.hadoop.yarn.exceptions.YarnRuntimeException: java.lang.NullPointerException
org.apache.hadoop.yarn.exceptions.YarnRuntimeException: java.lang.NullPointerException
at org.apache.hadoop.mapreduce.v2.app.rm.RMCommunicator.register(RMCommunicator.java:177)
at org.apache.hadoop.mapreduce.v2.app.rm.RMCommunicator.serviceStart(RMCommunicator.java:121)
at org.apache.hadoop.mapreduce.v2.app.rm.RMContainerAllocator.serviceStart(RMContainerAllocator.java:274)
at org.apache.hadoop.service.AbstractService.start(AbstractService.java:194)
at org.apache.hadoop.mapreduce.v2.app.MRAppMaster$ContainerAllocatorRouter.serviceStart(MRAppMaster.java:959)
at org.apache.hadoop.service.AbstractService.start(AbstractService.java:194)
at org.apache.hadoop.service.CompositeService.serviceStart(CompositeService.java:121)
at org.apache.hadoop.mapreduce.v2.app.MRAppMaster.serviceStart(MRAppMaster.java:1272)
...
at org.apache.hadoop.mapreduce.v2.app.MRAppMaster.initAndStartAppMaster(MRAppMaster.java:1719)
at org.apache.hadoop.mapreduce.v2.app.MRAppMaster.main(MRAppMaster.java:1650)
Caused by: java.lang.NullPointerException
at org.apache.hadoop.mapreduce.v2.app.client.MRClientService.getHttpPort(MRClientService.java:177)
at org.apache.hadoop.mapreduce.v2.app.rm.RMCommunicator.register(RMCommunicator.java:156)
... 14 more
2018-06-04 16:00:58,707 INFO [main] org.apache.hadoop.service.AbstractService: Service org.apache.hadoop.mapreduce.v2.app.MRAppMaster failed in state STARTED; cause: org.apache.hadoop.yarn.exceptions.YarnRuntimeException: java.lang.NullPointerException
org.apache.hadoop.yarn.exceptions.YarnRuntimeException: java.lang.NullPointerException
at org.apache.hadoop.mapreduce.v2.app.rm.RMCommunicator.register(RMCommunicator.java:177)
at org.apache.hadoop.mapreduce.v2.app.rm.RMCommunicator.serviceStart(RMCommunicator.java:121)
at org.apache.hadoop.mapreduce.v2.app.rm.RMContainerAllocator.serviceStart(RMContainerAllocator.java:274)
at org.apache.hadoop.service.AbstractService.start(AbstractService.java:194)
at org.apache.hadoop.mapreduce.v2.app.MRAppMaster$ContainerAllocatorRouter.serviceStart(MRAppMaster.java:959)
at org.apache.hadoop.service.AbstractService.start(AbstractService.java:194)
at org.apache.hadoop.service.CompositeService.serviceStart(CompositeService.java:121)
at org.apache.hadoop.mapreduce.v2.app.MRAppMaster.serviceStart(MRAppMaster.java:1272)
...
at org.apache.hadoop.mapreduce.v2.app.MRAppMaster.initAndStartAppMaster(MRAppMaster.java:1719)
at org.apache.hadoop.mapreduce.v2.app.MRAppMaster.main(MRAppMaster.java:1650)
Caused by: java.lang.NullPointerException
at org.apache.hadoop.mapreduce.v2.app.client.MRClientService.getHttpPort(MRClientService.java:177)
at org.apache.hadoop.mapreduce.v2.app.rm.RMCommunicator.register(RMCommunicator.java:156)
... 14 more

2018-06-04 16:01:04,015 FATAL [main] org.apache.hadoop.mapreduce.v2.app.MRAppMaster: Error starting MRAppMaster
org.apache.hadoop.yarn.exceptions.YarnRuntimeException: java.lang.NullPointerException
at org.apache.hadoop.mapreduce.v2.app.rm.RMCommunicator.register(RMCommunicator.java:177)
at org.apache.hadoop.mapreduce.v2.app.rm.RMCommunicator.serviceStart(RMCommunicator.java:121)
at org.apache.hadoop.mapreduce.v2.app.rm.RMContainerAllocator.serviceStart(RMContainerAllocator.java:274)
at org.apache.hadoop.service.AbstractService.start(AbstractService.java:194)
at org.apache.hadoop.mapreduce.v2.app.MRAppMaster$ContainerAllocatorRouter.serviceStart(MRAppMaster.java:959)
at org.apache.hadoop.service.AbstractService.start(AbstractService.java:194)
at org.apache.hadoop.service.CompositeService.serviceStart(CompositeService.java:121)
at org.apache.hadoop.mapreduce.v2.app.MRAppMaster.serviceStart(MRAppMaster.java:1272)
at org.apache.hadoop.service.AbstractService.start(AbstractService.java:194)
at org.apache.hadoop.mapreduce.v2.app.MRAppMaster$5.run(MRAppMaster.java:1723)
...
at org.apache.hadoop.mapreduce.v2.app.MRAppMaster.initAndStartAppMaster(MRAppMaster.java:1719)
at org.apache.hadoop.mapreduce.v2.app.MRAppMaster.main(MRAppMaster.java:1650)
Caused by: java.lang.NullPointerException
at org.apache.hadoop.mapreduce.v2.app.client.MRClientService.getHttpPort(MRClientService.java:177)
at org.apache.hadoop.mapreduce.v2.app.rm.RMCommunicator.register(RMCommunicator.java:156)
... 14 more
2018-06-04 16:01:04,016 INFO [main] org.apache.hadoop.util.ExitUtil: Exiting with status 1: org.apache.hadoop.yarn.exceptions.YarnRuntimeException: java.lang.NullPointerException

我根据这些信息也没找到解决方案，困扰好久了，希望各位大佬能够帮我看看哪里有问题，感激不尽

[_zhqy]

我在虚拟机的伪分布式是可以正常运行的，但到服务器上就跑不起来了，不知道该怎么解决，求大佬帮忙

[cheng1483]

是否配置了高可用HA， 配置高可用的话
问题大概就是MRClientService的WebApp创建过程出错，导致WebApp对象为null，后边调用了WebApp的getHttpPort()方法，导致空指针

HA机制下yarn-site.xml需要加入以下配置:
---------------------------------------------------
<property>
<name>yarn.resourcemanager.webapp.address.rm1</name>
<value>xxx1:8088</value>
</property>

<property>
<name>yarn.resourcemanager.webapp.address.rm2</name>
<value>xxx2:8088</value>
</property>

---------------------------------------------------
其中xxx1和xxx2需要替换成你的ResourceManager的主机名，比较坑的的就是即使你不配置，一样可以访问到管理界面，但是运行就会报错，增加了这一个配置以后，mapreduce程序就可以正常运行了。

见 https://blog.csdn.net/qq_38337823/article/details/80580422

[幸福的七星瓢虫]

我也遇到了同样的问题，请问你的解决了吗？ 楼上说的也配置了 但还是有问题。。。求大神解决啊