我有一个hadoop集群（hdp2.1）。一切都运行了很长一段时间，但突然乔布斯开始返回以下反复出现的错误：

16/10/13 16:21:11 INFO Configuration.deprecation: fs.default.name is deprecated. Instead, use fs.defaultFS
16/10/13 16:21:12 INFO Configuration.deprecation: fs.default.name is deprecated. Instead, use fs.defaultFS
16/10/13 16:21:12 INFO impl.TimelineClientImpl: Timeline service address: http://dev-fiwr-bignode-12.hi.inet:8188/ws/v1/timeline/
16/10/13 16:21:13 INFO client.RMProxy: Connecting to ResourceManager at dev-fiwr-bignode-12.hi.inet/10.95.76.79:8050
16/10/13 16:21:13 INFO input.FileInputFormat: Total input paths to process : 2
16/10/13 16:21:13 INFO mapreduce.JobSubmitter: number of splits:2
16/10/13 16:21:13 INFO Configuration.deprecation: fs.default.name is deprecated. Instead, use fs.defaultFS
16/10/13 16:21:14 INFO mapreduce.JobSubmitter: Submitting tokens for job: job_1476366871137_0003
16/10/13 16:21:14 INFO impl.YarnClientImpl: Submitted application application_1476366871137_0003
16/10/13 16:21:14 INFO mapreduce.Job: The url to track the job: http://dev-fiwr-bignode-12.hi.inet:8088/proxy/application_1476366871137_0003/
16/10/13 16:21:14 INFO mapreduce.Job: Running job: job_1476366871137_0003
16/10/13 16:21:19 INFO mapreduce.Job: Job job_1476366871137_0003 running in uber mode : false
16/10/13 16:21:19 INFO mapreduce.Job:  map 0% reduce 0%
16/10/13 16:21:23 INFO mapreduce.Job:  map 50% reduce 0%
16/10/13 16:21:24 INFO mapreduce.Job:  map 100% reduce 0%
16/10/13 16:21:28 INFO mapreduce.Job:  map 100% reduce 100%\
6/10/13 16:21:29 INFO mapred.ClientServiceDelegate: Application state is completed. FinalApplicationStatus=SUCCEEDED. Redirecting to job history server
16/10/13 16:21:29 INFO mapred.ClientServiceDelegate: Application state is completed. FinalApplicationStatus=SUCCEEDED. Redirecting to job history server
16/10/13 16:21:29 INFO mapred.ClientServiceDelegate: Application state is completed. FinalApplicationStatus=SUCCEEDED. Redirecting to job history server
Exception in thread \"main\" java.io.IOException:
org.apache.hadoop.ipc.RemoteException(java.lang.NullPointerException): java.lang.NullPointerException
org.apache.hadoop.mapreduce.v2.hs.HistoryClientService$HSClientProtocolHandler.getTaskAttemptCompletionEvents(HistoryClientService.java:277)
org.apache.hadoop.mapreduce.v2.api.impl.pb.service.MRClientProtocolPBServiceImpl.getTaskAttemptCompletionEvents(MRClientProtocolPBServiceImpl.java:173)
org.apache.hadoop.yarn.proto.MRClientProtocol$MRClientProtocolService$2.callBlockingMethod(MRClientProtocol.java:283)
org.apache.hadoop.ipc.ProtobufRpcEngine$Server$ProtoBufRpcInvoker.call(ProtobufRpcEngine.java:585)
org.apache.hadoop.ipc.RPC$Server.call(RPC.java:928)
org.apache.hadoop.ipc.Server$Handler$1.run(Server.java:2013)
org.apache.hadoop.ipc.Server$Handler$1.run(Server.java:2009)
java.security.AccessController.doPrivileged(Native Method)
javax.security.auth.Subject.doAs(Subject.java:415)
org.apache.hadoop.security.UserGroupInformation.doAs(UserGroupInformation.java:1594)
org.apache.hadoop.ipc.Server$Handler.run(Server.java:2007)
org.apache.hadoop.mapred.ClientServiceDelegate.invoke(ClientServiceDelegate.java:334)
org.apache.hadoop.mapred.ClientServiceDelegate.getTaskCompletionEvents(ClientServiceDelegate.java:386)
org.apache.hadoop.mapred.YARNRunner.getTaskCompletionEvents(YARNRunner.java:539)
org.apache.hadoop.mapreduce.Job$5.run(Job.java:668)
org.apache.hadoop.mapreduce.Job$5.run(Job.java:665)
java.security.AccessController.doPrivileged(Native Method)
javax.security.auth.Subject.doAs(Subject.java:415)
org.apache.hadoop.security.UserGroupInformation.doAs(UserGroupInformation.java:1594)
org.apache.hadoop.mapreduce.Job.getTaskCompletionEvents(Job.java:665)
org.apache.hadoop.mapreduce.Job.monitorAndPrintJob(Job.java:1366)
org.apache.hadoop.mapreduce.Job.waitForCompletion(Job.java:1306)
dijkstra.adjacencylist.AdjacencyListDriver.jobRun(AdjacencyListDriver.java:53)
dijkstra.adjacencylist.AdjacencyListDriver.run(AdjacencyListDriver.java:31)
org.apache.hadoop.util.ToolRunner.run(ToolRunner.java:70)
org.apache.hadoop.util.ToolRunner.run(ToolRunner.java:84)
dijkstra.launch.LaunchClass.launchAdjMatrix(LaunchClass.java:226)
dijkstra.launch.LaunchClass.main(LaunchClass.java:199)
sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:57)
sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
java.lang.reflect.Method.invoke(Method.java:606)
org.apache.hadoop.util.RunJar.main(RunJar.java:212)
Caused by:
org.apache.hadoop.ipc.RemoteException(java.lang.NullPointerException):
java.lang.NullPointerException
org.apache.hadoop.mapreduce.v2.hs.HistoryClientService$HSClientProtocolHandler.getTaskAttemptCompletionEvents(HistoryClientService.java:277)
...

谷歌一下，我看到了这些问题：
https://issues.apache.org/jira/browse/mapreduce-5703
https://issues.apache.org/jira/browse/mapreduce-5547
他们似乎有关系。然而，为什么集群到目前为止运行正常？配置中没有任何更改，clsuter未处于安全模式，hdfs空间使用率约为0.03%。。。有什么线索吗？如果这与上述问题有关，有什么解决办法吗？
非常感谢，我将继续关注您的答案或其他信息要求。