How to fix Mamp server bug

When I work on Wordpress development with Mamp (OSX), I sometimes have a problem : only Apache server wants start, even if I quit and relaunch. It's probably due to conflict with other programs and livereload stuff I use to.
I found an efficient solution in a forum.

Close Mamp and open your Terminal :

# 1
ps aux | grep mysql 
# 2
lsof -i 
# 3
killall -9 mysqld 

Now open Mamp, start servers and it'll be ok.