A dirty hack but essential at times, MySQL server consumes higher memory if not configured correctly and due to which the MySQL service is terminated by the OS to save itself from crashing under high traffic.
A simple shell script can be used to restart MySQL service when it terminated.
Download this script using wget
Make the script executable
sudo chmod +x mysql-monitor.sh
Execute this script each minute with a crontab
sudo crontab -e
*/1 * * * * sh /path/to/script/mysql-monitor.sh