Updating MYSQL 5.5 -> 5.7

To add ejabberd and run MYSQL to the server I needed to update the server version of mysql from 5.5 to 5.7.  Fortunately, there are great instructions on the Plesk support page regarding how to achieve this outcome.

https://support.plesk.com/hc/en-us/articles/213403429-How-to-upgrade-MySQL-5-5-to-5-6-5-7-or-MariaDB-5-5-to-10-0-10-1-10-2-on-Linux

As a point of reference, as I worked through the steps... step 10 you need to restart the MYSQL server.  This is a quick progress by running the following command

service mysqld start

However, for me it failed.  To correct this I needed to edit the my.cnf file located in the etc directory (/etc/my.cnf).

vi /etc/my.cnf

Search for the line innodb_additional_mem_pool_size=500K and comment it out.  Save the file and try to restart the MYSQL server

service mysqld start

Now working as anticipated, so I could move on and complete steps 11 and 12.