在安装hadoop之后，我尝试启动一个相当简单的wordcount（我基本上遵循了本教程），但我得到了以下结果：

2018-04-05 16:51:00,192 INFO mapreduce.Job: Job job_1522936330711_0007 failed with state FAILED due to: Application application_1522936330711_0007 failed 2 times due to AM Container for appattempt_1522936330711_0007_000002 exited with  exitCode: 1
Failing this attempt.Diagnostics: [2018-04-05 16:50:59.449]Exception from container-launch.
Container id: container_1522936330711_0007_02_000001
Exit code: 1

[2018-04-05 16:50:59.452]Container exited with a non-zero exit code 1. Error file: prelaunch.err.
Last 4096 bytes of prelaunch.err :
Last 4096 bytes of stderr :
Error : Could not find or load main class org.apache.hadoop.mapreduce.v2.app.MRAppMaster

[2018-04-05 16:50:59.452]Container exited with a non-zero exit code 1. Error file: prelaunch.err.
Last 4096 bytes of prelaunch.err :
Last 4096 bytes of stderr :
Error : Could not find or load main class org.apache.hadoop.mapreduce.v2.app.MRAppMaster

For more detailed output, check the application tracking page: http://iMac-de-chaire-2.local:8088/cluster/app/application_1522936330711_0007 Then click on links to logs of each attempt.
. Failing the application.
2018-04-05 16:51:00,211 INFO mapreduce.Job: Counters: 0

当我尝试访问日志时，它会告诉我 "Failed to read the attempts of the application application_1522940117199_0001." 我有以下文件： hadoop-env.sh :

export HADOOP_HOME=/usr/local/hadoop/

export HADOOP_COMMON_HOME=$HADOOP_HOME
export HADOOP_HDFS_HOME=$HADOOP_HOME
export HADOOP_MAPRED_HOME=$HADOOP_HOME
export YARN_HOME=$HADOOP_HOME
export HADOOP_OPTS="-Djava.library.path=$HADOOP_HOME/lib/native"
export HADOOP_COMMON_LIB_NATIVE_DIR=$HADOOP_HOME/lib/native
``` `yarn-site.xml` :