我已经安装了hadoop2.7.3稳定版。我设置了所有环境变量，如java\u home、hadoop\u home、path等。。我配置了yarn-site.xml、hdfs-site.xml、core-site.xml、mapred-site.xml。
我上传了hdfs中的示例文件。当我在hadoop-mapreduce-examples-2.7.3.jar中使用以下命令执行wordcount程序时

bin/hadoop jar share/hadoop/mapreduce/hadoop-mapreduce-examples-2.7.3.jar grep input output 'as[a-z.]+'

它引发了以下异常。

17/01/28 00:59:33 INFO input.FileInputFormat: Total input paths to process : 36
    17/01/28 00:59:33 INFO mapreduce.JobSubmitter: number of splits:36
    17/01/28 00:59:33 INFO mapreduce.JobSubmitter: Submitting tokens for job: job_1485582326336_0001
    17/01/28 00:59:34 INFO impl.YarnClientImpl: Submitted application application_1485582326336_0001
    17/01/28 00:59:34 INFO mapreduce.Job: The url to track the job: http://XXXX.local:8088/proxy/application_1485582326336_0001/
    17/01/28 00:59:34 INFO mapreduce.Job: Running job: job_1485582326336_0001
    17/01/28 00:59:38 INFO mapreduce.Job: Job job_1485582326336_0001 running in uber mode : false
    17/01/28 00:59:38 INFO mapreduce.Job:  map 0% reduce 0%
    17/01/28 00:59:38 INFO mapreduce.Job: Job job_1485582326336_0001 failed with state FAILED due to: Application application_1485582326336_0001 failed 2 times due to AM Container for appattempt_1485582326336_0001_000002 exited with  exitCode: 127
    For more detailed output, check application tracking page:http://XXXXXX.local:8088/cluster/app/application_1485582326336_0001Then, click on links to logs of each attempt.
    Diagnostics: Exception from container-launch.
    Container id: container_1485582326336_0001_02_000001
    Exit code: 127
    Stack trace: ExitCodeException exitCode=127: 
        at org.apache.hadoop.util.Shell.runCommand(Shell.java:582)
        at org.apache.hadoop.util.Shell.run(Shell.java:479)
        at org.apache.hadoop.util.Shell$ShellCommandExecutor.execute(Shell.java:773)
        at org.apache.hadoop.yarn.server.nodemanager.DefaultContainerExecutor.launchContainer(DefaultContainerExecutor.java:212)
        at org.apache.hadoop.yarn.server.nodemanager.containermanager.launcher.ContainerLaunch.call(ContainerLaunch.java:302)
        at org.apache.hadoop.yarn.server.nodemanager.containermanager.launcher.ContainerLaunch.call(ContainerLaunch.java:82)
        at java.util.concurrent.FutureTask.run(FutureTask.java:266)
        at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1142)
        at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:617)
        at java.lang.Thread.run(Thread.java:745)

    Container exited with a non-zero exit code 127
    Failing this attempt. Failing the application.
    17/01/28 00:59:38 INFO mapreduce.Job: Counters: 0
    17/01/28 00:59:38 INFO client.RMProxy: Connecting to ResourceManager at /0.0.0.0:8032
    17/01/28 00:59:38 INFO mapreduce.JobSubmitter: Cleaning up the staging area /tmp/hadoop-yarn/staging/sumitdeshmukh/.staging/job_1485582326336_0002
    org.apache.hadoop.mapreduce.lib.input.InvalidInputException: Input path does not exist: hdfs://localhost:9000/user/<username>/grep-temp-155204726

这个问题有什么解决办法吗？