"Authentication plugin 'caching_sha2_password' cannot be loaded: /

Question

va"Authentication plugin 'caching_sha2_password' cannot be loaded: /usr/lib/mysql/plugin/caching_sha2_password.so: cannot open shared object file: No such file or directory"

i got this error when i try to connect to mysql from emma or mysql bench on ubuntu 18.04

There is similar issue but it is for windows

https://stackoverflow.com/questions/49963383/authentication-plugin-caching-sha2-password

i tried to reinstall and this

https://stackoverflow.com/a/50027851/9658011

but did not work.

What can i do?

Answer 1

Use this query:

ALTER USER 'root'@'localhost' IDENTIFIED WITH mysql_native_password BY 'YourPassword';

You don't get caching_sha2_password.
Then connect to MySQL.

Answer 2

I solved. I installed mysql 5.7 on 18.04, not latest version.

738  sudo apt-get purge mysql-server mysql-client mysql-common mysql-server-core- mysql-client-core-
  739  sudo rm -rf /etc/mysql /var/lib/mysql
  740  sudo apt-get autoremove
  741  sudo apt-get autoclean
  742  sudo apt install mysql-client-5.7
  743  sudo apt install mysql-common-5.7
  744  sudo apt install mysql-common
  745  sudo apt install mysql-common-5.7
  746  sudo apt install mysql-client-5.7
  747  systemctl status mysql.service
  748  sudo add-apt-repository 'deb http://archive.ubuntu.com/ubuntu trusty universe'
  749  sudo apt install mysql-client-5.7
  750  sudo apt install mysql-server-5.7
  751  sudo apt install mysql-common-5.8
  752  sudo apt-get purge mysql-client-core-5.6
  753  sudo apt-get autoremove
  754  sudo apt-get autoclean
  755  sudo apt install mysql-client-core-5.5

None of previos worked. So i did those and worked:

  756  sudo apt install mysql-client-core-5.6
  757  sudo apt install mysql-server  
  758  mysql_secure_installation
  759  mysql -u root -p

Answer 3

I used

sudo tasksel install lamp-server

mode method, so instead I tend to retain this installation as is, intact.