How does it handle failure of the slave? If the read queries can't quickly fail back to running on the master, I'd rather just keep using a single server.
Be sure to test it out with a read-only user querying the slave. If there's any sign that a write query makes its way to a slave, we can't use this.
If this works, it gives us a way to do some horizontal scaling of our database load.
https://www.drupal.org/project/autoslave
If this works, it gives us a way to do some horizontal scaling of our database load.