Cell Background colour not showing in LibreOffice Calc

This can be resolved in Tools>Options>LibreOffice>Accessibility and ensuring that Options For High Contrast Appearance is Disabled, as below;

Add custom command to nagios

 In this example, we add the plugin to check MySQL replication status [source]

Show mysql variables

We can show mysql variables with the following;

SHOW VARIABLES WHERE variable_name = 'some_variable';

SHOW VARIABLES LIKE '%some_variable%';

Example, to show the number of days binary logs are retained for;

SHOW VARIABLES WHERE variable_name = 'expire_logs_days';