SMTP error after mariaDB upgrade

[mohamedh]

Hi,


I updated my server from mysql 5.5 mariadb to mariaDB 10.2 following these steps.
https://www.tecmint.com/upgrade-mariadb-...an-ubuntu/

Soon after I finished the installation and rebooted my server I tried logging in roundcube but I got

"Connection to storage server failed"

I checked the logs and I figured that dovecot needs the mysql module
so I did

Code:

yum install dovecot-mysql

Now I can login to roundcube to view old mails, but when I try to send  I get

SMTP Error (-1): Connection to server failed.

.
I can't receive neither. Also the issue happens on my phone too, when sending I get "connecting to outgoing server failed" and I can't receive.

tail /var/log/dovecot.log gives the following:

2019-02-03 12:24:20master: Error: service(auth): command startup failed, throttling for 60 secs
2019-02-03 12:24:40imap-login: Warning: Auth process not responding, delayed sending initial response (greeting): user=<>, rip=127.0.0.1, lip=127.0.0.1, secured, session=<X9A/n/uAfNZ/AAAB>
2019-02-03 12:25:00imap-login: Error: Timeout waiting for handshake from auth server. my pid=9996, input bytes=0
2019-02-03 12:25:20master: Error: service(auth): command startup failed, throttling for 60 secs
2019-02-03 12:25:20auth: Fatal: Unknown database driver 'mysql'
2019-02-03 12:29:48auth: Fatal: Unknown database driver 'mysql'
2019-02-03 12:29:48master: Error: service(auth): command startup failed, throttling for 2 secs
2019-02-03 12:33:39auth: Fatal: Unknown database driver 'mysql'
2019-02-03 12:33:39master: Error: service(auth): command startup failed, throttling for 4 secs
2019-02-03 12:54:09master: Warning: Killed with signal 15 (by pid=13322 uid=0 code=kill)

Does anyone know what the issue is? I don't want to try random solutions from the internet since this is a production server.