1

One example of this is the innodb_log_file_size configuration option. As discussed here, there are a series of steps that starts an hour before shutdown and goes to after shutting down. However, this doesn't appear to be documented in the MySQL documentation for this variable and I don't see a list of variables that you may not be able to adjust by simply editing the configuration file and restarting the server.

Does such a list of variables exist? What variables do I need to potentially watch when tuning MySQL to ensure compatibility with existing binary backups?

Community
  • 1
Thomas Owens
  • 113
  • 5

1 Answers1

2

It depends on which version you are using. By the time you get to 8.0, virtually everything can be dynamically changed. Here are 2 types of pages, each with a list. Note the version number in the URL; change as needed.

http://dev.mysql.com/doc/refman/5.7/en/dynamic-system-variables.html

https://dev.mysql.com/doc/refman/5.5/en/server-system-variables.html -- Note the "Dynamic" column.

innodb_log_file_size used to be one of the worst settings to change. You could not simply change the config and restart -- the server would complain that the size does not match. Recently (sorry, don't know what version), the 'right thing' would be done with the files. But it still required a restart.

In my experience, 90% of users can get away with setting innodb_buffer_pool_size based on RAM size, then ignore the rest of the settings.

(If you wanted to talk specifically about innodb parameters, say so.)

If you want a critique of your settings, provide RAM size, SHOW VARIABLES; and SHOW GLOBAL STATUS; after it has been up at least a day. I have about 150 formulas to test; they typically lead to 5-10 recommended changes of the VARIABLES.

Rick James
  • 80,479
  • 5
  • 52
  • 119