MySQL 5.7 introduces a change in the way we query for global variables and status variables: the INFORMATION_SCHEMA.(GLOBAL|SESSION)_(VARIABLES|STATUS) tables are now deprecated and empty. Instead, we are to use the respective performance_schema.(global|session)_(variables|status) tables.
But the change goes farther than that; there is also a security change. Oracle created a pitfall of 2 changes at the same time:
- Variables/status moved to a different table
- Privileges required on said table
As an example, my non-root user gets:
mysql> show session variables like 'tx_isolation'; ERROR 1142 (42000): SELECT command denied to user 'normal_user'@'my_host' for table 'session_variables'
Who gets affected by this? Nearly everyone and everything.
- Your Nagios will not be able to read …