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 start 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
 

EDIT:

here is what i am seeing now:

# systemctl  status  -l  mariadb.service  ;   ## restart mariadb
● 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: activating (start) since Sun 2019-10-06 18:31:14 EDT; 43s ago
     Docs: man:mysqld(8)
           https://mariadb.com/kb/en/library/systemd/
  Process: 10240 ExecStartPost=/bin/sh -c systemctl unset-environment _WSREP_START_POSITION (code=exited, status=0/SUCCESS)
  Process: 13399 ExecStartPre=/bin/sh -c [ ! -e /usr/bin/galera_recovery ] && VAR= ||   VAR=`/usr/bin/galera_recovery`; [ $? -eq 0 ]   && systemctl set-environment _WSREP_START_POSITION=$VAR || exit 1 (code=exited, status=0/SUCCESS)
  Process: 13320 ExecStartPre=/bin/sh -c systemctl unset-environment _WSREP_START_POSITION (code=exited, status=0/SUCCESS)
 Main PID: 13455 (mysqld)
   CGroup: /system.slice/mariadb.service
           └─13455 /usr/sbin/mysqld

Oct 06 18:31:37 edwardsmark.info mysqld[13455]: 2019-10-06 18:31:32 140379062454464 [Note] InnoDB: Using Linux native AIO
Oct 06 18:31:37 edwardsmark.info mysqld[13455]: 2019-10-06 18:31:32 140379062454464 [Note] InnoDB: Number of pools: 1
Oct 06 18:31:37 edwardsmark.info mysqld[13455]: 2019-10-06 18:31:32 140379062454464 [Note] InnoDB: Using SSE2 crc32 instructions
Oct 06 18:31:37 edwardsmark.info mysqld[13455]: 2019-10-06 18:31:32 140379062454464 [Note] InnoDB: Initializing buffer pool, total size = 128M, instances = 1, chunk size = 128M
Oct 06 18:31:37 edwardsmark.info mysqld[13455]: 2019-10-06 18:31:32 140379062454464 [Note] InnoDB: Completed initialization of buffer pool
Oct 06 18:31:37 edwardsmark.info mysqld[13455]: 2019-10-06 18:31:32 140378200946432 [Note] InnoDB: If the mysqld execution user is authorized, page cleaner thread priority can be changed. See the man page of setpriority().
Oct 06 18:31:37 edwardsmark.info mysqld[13455]: 2019-10-06 18:31:34 140379062454464 [Note] InnoDB: Highest supported file format is Barracuda.
Oct 06 18:31:37 edwardsmark.info mysqld[13455]: 2019-10-06 18:31:35 140379062454464 [Note] InnoDB: Starting crash recovery from checkpoint LSN=38062514322
Oct 06 18:31:13 edwardsmark.info systemd[1]: Stopped MariaDB 10.2.27 database server.
Oct 06 18:31:14 edwardsmark.info systemd[1]: Starting MariaDB 10.2.27 database server...

AND ANOTHER CRASH!

# systemctl  status  -l  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 18:38:58 EDT; 6min ago
     Docs: man:mysqld(8)
           https://mariadb.com/kb/en/library/systemd/
  Process: 10240 ExecStartPost=/bin/sh -c systemctl unset-environment _WSREP_START_POSITION (code=exited, status=0/SUCCESS)
  Process: 14236 ExecStart=/usr/sbin/mysqld $MYSQLD_OPTS $_WSREP_NEW_CLUSTER $_WSREP_START_POSITION (code=exited, status=0/SUCCESS)
  Process: 14026 ExecStartPre=/bin/sh -c [ ! -e /usr/bin/galera_recovery ] && VAR= ||   VAR=`/usr/bin/galera_recovery`; [ $? -eq 0 ]   && systemctl set-environment _WSREP_START_POSITION=$VAR || exit 1 (code=exited, status=0/SUCCESS)
  Process: 13898 ExecStartPre=/bin/sh -c systemctl unset-environment _WSREP_START_POSITION (code=exited, status=0/SUCCESS)
 Main PID: 14236 (code=exited, status=0/SUCCESS)
   Status: "MariaDB server is down"

Oct 06 18:38:53 edwardsmark.info mysqld[14236]: 2019-10-06 18:38:53 139696513103616 [Note] InnoDB: FTS optimize thread exiting.
Oct 06 18:38:54 edwardsmark.info mysqld[14236]: 191006 18:38:54 server_audit: STOPPED
Oct 06 18:38:56 edwardsmark.info mysqld[14236]: 2019-10-06 18:38:56 139696652347136 [Note] InnoDB: Starting shutdown...
Oct 06 18:38:56 edwardsmark.info mysqld[14236]: 2019-10-06 18:38:56 139696403367680 [Note] InnoDB: Buffer pool(s) load completed at 191006 18:38:56
Oct 06 18:38:56 edwardsmark.info mysqld[14236]: 2019-10-06 18:38:56 139696403367680 [Note] InnoDB: Dumping buffer pool(s) to /var/lib/mysql/ib_buffer_pool
Oct 06 18:38:56 edwardsmark.info mysqld[14236]: 2019-10-06 18:38:56 139696403367680 [Note] InnoDB: Buffer pool(s) dump completed at 191006 18:38:56
Oct 06 18:38:58 edwardsmark.info mysqld[14236]: 2019-10-06 18:38:57 139696652347136 [Note] InnoDB: Shutdown completed; log sequence number 38062514359
Oct 06 18:38:58 edwardsmark.info systemd[1]: Failed to start MariaDB 10.2.27 database server.
Oct 06 18:38:58 edwardsmark.info systemd[1]: Unit mariadb.service entered failed state.
Oct 06 18:38:58 edwardsmark.info systemd[1]: mariadb.service failed.