Why commands are executing slowly?

Issue

• Few commands like uptime and who are executing slowly.

[root@example ~]# time uptime
 13:07:56 up 491 days,  2:59,  2 users,  load average: 0.53, 0.21, 0.09

real    0m2.205s
user    0m0.285s
sys     0m1.867s

[root@example ~]# time who
root     pts/7        2018-06-08 09:37 
root     pts/0        2018-06-08 13:07 

real    0m2.360s
user    0m0.353s
sys     0m1.954s

[root@example ~]# time date
Fri Jun  8 13:10:40 BST 2018

real    0m0.002s
user    0m0.000s
sys     0m0.002s

The commands who and uptime are taking around 2 seconds to execute whereas the date command gets executed in less than a second.