MySql - Read only on slave

I want to make my MySql slave read only, i've been looking and found the read_only option, but its says that users with super privalges can still write (if i understand the text correctly), here is the grants for my app:

GRANT RELOAD, PROCESS ON *.* TO 'my_app'@'%' IDENTIFIED BY PASSWORD '*'
GRANT ALL PRIVILEGES ON `my_app`.* TO 'my_app'@'%'

will the app be able to write to the slave?

Here are the grants you just mentioned

GRANT RELOAD, PROCESS ON *.* TO 'my_app'@'%' IDENTIFIED BY PASSWORD '*'
GRANT ALL PRIVILEGES ON `my_app`.* TO 'my_app'@'%'

Based on this, you should not be able to write to the Slave because SUPER is a system level privilege (SUPER only appears in mysql.user as Super_priv) and not a DB level privilege (SUPER does not appear in mysql.db). The first GRANT lacks SUPER privilege. The second GRANT does not have a SUPER privilege context at all.

Having SUPER privilege has a lot of firepower because you can run the following

• CHANGE MASTER TO

• KILL

• SET GLOBAL

• PURGE BINARY LOGS

Not every user needs this. Giving the SUPER privilege to just anyone can actually hamper a DBA from logging into mysql if max_connections is reached.

StackExchange Database Administrators Q#14455, answer score: 4