The most common reason for MySQL to crash like this is that the process is running out of memory. Rather than treat the symptom by restarting the process (this will eventually lead to data corruption due to the crashes) we can treat the cause. There are a couple things you can do.

1.) Set up a swap file on your droplet. This file will be used when your physical memory is exhausted, swapping data out here rather than allowing services to crash.

2.) Optimize the processes running on your droplet. A number of tutorials on optimizing various apps can be found here.

3.) Finally, you can choose to upgrade to a droplet plan which provides more RAM.

A useful command while doing this is

free -m

This will display a summary of your used and available memory and help you to track how your changes and optimizations are affecting resource use.

if you have a cron job to restart apache and mysql sometimes the service can’t be correctly stopped, this is some kind of issue with users, so you need to kill the process, you can try to read pid file for process id and kill -9 that id, then restart.

Again as suggested, fix MySQL problem or this will solve nothing, only cause you a db corruption.

here some samples for restarts, you can try to add a counter of tries, if you restart X service more than 3 times in a row then #reboot:

#!/bin/bash

#Memcached if service memcached status | grep -q “running”; then echo “MemCached is up” else service memcached restart cat /root/alert.txt | mail -s “MemCached Service Down” myemail@gmail.com fi

#This if is just a sample of reboot, you need to use correct syntax here

#--------------------------------------------------------------------- if cat /root/count.txt = 111; then reboot fi #Sample end

#Nginx + counter if service nginx status | grep -q “running”; then echo “Nginx is up” echo 0 > /root/count.txt else service nginx restart cat /root/alert.txt | mail -s “Nginx Service Down” myemail@gmail.com echo 1 >> /root/count.txt fi

#---------------------------------------------------------------------

#PHP-FPM if service php-fpm status | grep -q “running”; then echo “PHP-FPM is up” else service php-fpm restart cat /root/alert.txt | mail -s “PHP-FPM Service Down” myemail@gmail.com fi

#PHP-FPM Max Children Status if curl -s http://site.com/status | grep -q “max children reached: 0”; then echo PHP running normal; else service php-fpm reload cat /root/alert.txt | mail -s “PHP-FPM Max Children reached!” myemail@gmail.com fi

thanks EpicCDN for your detailed answer :-)