hadoop执行任务常见问题

1.ERROR security.UserGroupInformation: PriviledgedActionException as: hadoop cause:java.io.IOException Failed to set permissions of path:\usr\hadoop\tmp\mapred\staging\hadoop753422487\.staging to 0700 Exception in thread "main" java.io.IOException: Failed to set permissions of path: \usr\hadoop\tmp \mapred\staging\hadoop753422487\.staging to 0700

　　　解决方法：

Configuration conf = new Configuration();
conf.set("mapred.job.tracker", "[server]:9001");

2.mapred.JobClient: No job jar file set.  User classes may not be found. See JobConf(Class) or JobConf
解决办法：

将本工程导出jar包放到工程根目录下面，并在提交程序前添加下面的设置

conf.set("mapred.jar", "loadforecast_utils.jar"); //其中loadforecast_utils.jar是你的导出的jar文件名。注意第一个参数不要拼写错了。