[Hadoop] Hadoop yarn Configuration method to display debug debug information __yarn

1. By default, the Yarn log only displays info and above level information, and it is necessary to display the necessary debug information when the system is developed two times.

2. Configure yarn to print debug information to the log file, just modify its startup script sbin/yarn-daemon.sh, and change the info to debug (this step only).

  Export Yarn_root_logger=${yarn_root_logger:-debug,rfa}

3. For HDFs, the modification method is similar, only need to modify the sbin/hadoop-daemon.sh, replace the info with Debug.

  Export hadoop_root_logger=${hadoop_root_logger:-"Debug,rfa"}
  export hadoop_security_logger=${hadoop_security _logger:-"Debug,rfas"}
  export hdfs_audit_logger=${hdfs_audit_logger:-"Debug,nullappender"}