Rasmus Johansson <rasmus@mariadb.com> writes:

I received a question that I wanted to share here to get some insight on.

MariaDB 10.0 has a global setting named "slave_parallel_threads" and MySQL 5.7 has the same parameter named "slave_parallel_workers".

Should slave_parallel_workers be an alias to slave_parallel_threads in MariaDB 10.0 to be more compatible with MySQL?

I do not have any strong opinion on this, one way or the other. So I'm willing to change it to whatever people can argue is most appropriate. It is of course nice to be as compatible as possible, which speaks for having the alias (or why not simply change it to be the same as the MySQL one, it is a new feature in MariaDB, after all). What speaks against it is that the MariaDB parallel replication and MySQL parallel replication are _not_ the same. There are fairly big fundamental differences. So the question is if it is a good thing that one server will silently accept the option from one server, and make it do something somewhat different, which may or may not be what the user expects? Or is it better to give the user an error message, to be sure that she is aware of the difference between the two implementations? [Bcc:'ed the super secret person who originally asked this highly confidential question through the twisted channels of an NSA-wannabee MySQL support company </sarcasm>] - Kristian.