RoundCube -- DATABASE ERROR: CONNECTION FAILED!

IspConfig 3.2 Debian10. NGINX

Aparently I did not learn my lesson from the last time I ran out of diskspace attempting to write backup scripts.
https://www.howtoforge.com/community/threads/roundcube-configuration-error.86643/#post-420277

This time I get a different RoundCube error:
----------------------------------
DATABASE ERROR: CONNECTION FAILED!
Unable to connect to the database!
Please contact your server-administrator.
----------------------------------
cat mail.err
.
.
.
May 4 16:22:01 SERVER dovecot: auth-worker(2468): Error: mysql(localhost): Connect failed to database (dbispconfig): Can't connect to local MySQL server through socket '/var/run/mysqld/mysqld.sock' (111) - waiting for 25 seconds before retry

 

Try following https://www.howtoforge.com/community/threads/please-read-before-posting.58408/

 

Code:

    cat mail.err
    .
    .
    .
    May 4 16:22:01 SERVER dovecot: auth-worker(2468): Error: mysql(localhost): Connect failed to database (dbispconfig): Can't connect to local MySQL server through socket '/var/run/mysqld/mysqld.sock' (111) - waiting for 25 seconds before retry

 

Code:

root@mr2:/var/log/mysql# /etc/init.d/mysql status
● mariadb.service - MariaDB 10.3.27 database server
   Loaded: loaded (/lib/systemd/system/mariadb.service; enabled; vendor preset: enabled)
  Drop-In: /etc/systemd/system/mysql.service.d
           └─limits.conf
   Active: active (running) since Tue 2021-05-04 16:45:55 CDT; 5 days ago
     Docs: man:mysqld(8)
           https://mariadb.com/kb/en/library/systemd/
  Process: 610 ExecStartPre=/usr/bin/install -m 755 -o mysql -g root -d /var/run/mysqld (code=exited, status=0/SUCCESS)
  Process: 633 ExecStartPre=/bin/sh -c systemctl unset-environment _WSREP_START_POSITION (code=exited, status=0/SUCCESS)
  Process: 648 ExecStartPre=/bin/sh -c [ ! -e /usr/bin/galera_recovery ] && VAR= ||   VAR=`cd /usr/bin/..; /usr/bin/galera_recovery`; [ $? -eq 0 ]   && systemctl set-environment _WSREP_START_POSITION=$VAR || exit 1 (code=exited, status=0/SUCCESS)
  Process: 889 ExecStartPost=/bin/sh -c systemctl unset-environment _WSREP_START_POSITION (code=exited, status=0/SUCCESS)
  Process: 893 ExecStartPost=/etc/mysql/debian-start (code=exited, status=0/SUCCESS)
 Main PID: 703 (mysqld)
   Status: "Taking your SQL requests now..."
    Tasks: 55 (limit: 4915)
   Memory: 511.7M
   CGroup: /system.slice/mariadb.service
           └─703 /usr/sbin/mysqld

Mysql appears to be running.

IspConfig is running and RoundCube has recovered and is running.