报错：Hadoop Warning: fs.defaultFS is not set when running "ls" command.

报错背景

服务器安装了impala，然后hadoop命令就不能用了，hadoop fs -ls / 列出来的都是本地文件夹，而不是HDFS的文件夹。

同时，hbase、hive等命令也全都失效。

报错现象

[root@basecoalmine bin]# hdfs dfs -ls /
SLF4J: Class path contains multiple SLF4J bindings.
SLF4J: Found binding in [jar:file:/usr/lib/zookeeper/lib/slf4j-log4j12-1.7.5.jar!/org/slf4j/impl/StaticLoggerBinder.class]
SLF4J: Found binding in [jar:file:/opt/software/tez-0.9.2/lib/slf4j-log4j12-1.7.10.jar!/org/slf4j/impl/StaticLoggerBinder.class]
SLF4J: See http://www.slf4j.org/codes.html#multiple_bindings for an explanation.
SLF4J: Actual binding is of type [org.slf4j.impl.Log4jLoggerFactory]
Warning: fs.defaultFS is not set when running "ls" command.
Found 24 items
-rw-r--r--   1 root root          0 2022-01-23 04:20 /.autorelabel
dr-xr-xr-x   - root root      28672 2022-03-09 03:26 /bin
dr-xr-xr-x   - root root       4096 2022-01-23 04:20 /boot
drwxr-xr-x   - root root         62 2022-02-22 21:58 /data
drwxr-xr-x   - root root       3220 2022-01-23 04:20 /dev
drwxr-xr-x   - root root       8192 2022-03-08 23:45 /etc
drwxr-xr-x   - root root         20 2022-02-08 04:01 /home
dr-xr-xr-x   - root root       4096 2022-03-07 20:21 /lib
dr-xr-xr-x   - root root      36864 2022-03-07 20:19 /lib64
drwxr-xr-x   - root root         23 2022-02-11 03:03 /logs
drwxr-xr-x   - root root          6 2018-04-11 00:59 /media
drwxr-xr-x   - root root          6 2018-04-11 00:59 /mnt
drwxr-xr-x   - root root        117 2022-02-22 03:18 /opt
dr-xr-xr-x   - root root          0 2022-01-23 04:19 /proc
dr-xr-x---   - root root       4096 2022-03-09 03:23 /root
drwxr-xr-x   - root root        920 2022-03-08 23:18 /run
dr-xr-xr-x   - root root      16384 2022-03-07 01:11 /sbin
drwxr-xr-x   - root root          6 2018-04-11 00:59 /srv
dr-xr-xr-x   - root root          0 2022-01-25 01:01 /sys
drwxrwxrwt   - root root      12288 2022-03-09 03:27 /tmp
drwxr-xr-x   - root root         20 2022-03-08 23:08 /user
drwxr-xr-x   - root root        199 2022-01-25 00:25 /usr
drwxr-xr-x   - root root        278 2022-01-23 02:44 /var
-rw-r--r--   1 root root        958 2022-01-25 01:02 /zookeeper.out

报错原因

impala安装完成之后会在/usr/bin目录下生成它自己的hadoop、hive、hbase等相关命令，而且这个目录在环境变量的位置排在前面，自己安装的软件环境变量在后面，所以自己安装的软件环境变量会被覆盖，先执行impala的命令，导致命令找不到的情况发生。

报错解决

将impala的命令删除即可。

rm -rf /usr/bin/hadoop
rm -rf /usr/bin/hdfs
rm -rf /usr/bin/hbase
rm -rf /usr/bin/hive
rm -rf /usr/bin/hiveserver2