mariadb server mysteriously seems to be crashing

hello - the last couple of days my server seems to have mysteriously stopped. simply doing:

systemctl stop mariadb.service ; systemctl staart mariadb.service ;

seems to temporarily fix it. i am tempted to have something like this run in a cron job every hour just to be safe.

Server version: 10.2.27-MariaDB MariaDB Server

# systemctl  status  mariadb.service  ;  
● mariadb.service - MariaDB 10.2.27 database server
   Loaded: loaded (/usr/lib/systemd/system/mariadb.service; enabled; vendor preset: disabled)
  Drop-In: /etc/systemd/system/mariadb.service.d
           └─migrated-from-my.cnf-settings.conf
   Active: failed (Result: timeout) since Sun 2019-10-06 15:28:21 EDT; 2h 27min ago
     Docs: man:mysqld(8)
           https://mariadb.com/kb/en/library/systemd/
  Process: 20375 ExecStartPost=/bin/sh -c systemctl unset-environment _WSREP_START_POSITION (code=exited, status=0/SUCCESS)
  Process: 20343 ExecStart=/usr/sbin/mysqld $MYSQLD_OPTS $_WSREP_NEW_CLUSTER $_WSREP_START_POSITION (code=killed, signal=KILL)
  Process: 14181 ExecStartPre=/bin/sh -c [ ! -e /usr/bin/galera_recovery ] && VAR= ||   VAR=`/usr/bin/galera_recovery`; [ $? -eq 0 ]   && systemct                                              l set-environment _WSREP_START_POSITION=$VAR || exit 1 (code=killed, signal=TERM)
  Process: 14154 ExecStartPre=/bin/sh -c systemctl unset-environment _WSREP_START_POSITION (code=exited, status=0/SUCCESS)
 Main PID: 20343 (code=killed, signal=KILL)
   CGroup: /system.slice/mariadb.service