After creating a read replica, how does this effect my app? Do the benefits happen behind the scenes at aws or do I need to write logic for my application to know that it can read from this new replica instance?
Você precisa modificar seu aplicativo para enviar algumas ou todas as suas consultas SQL SELECT
para a nova réplica.
It mentions a "Brief I/O interruption" that can last up to a minute here Does that mean my production app is 'dead in the water' for up to a minute? Has anyone experienced anything longer than that?
Eu não vi mais que um minuto. Se você estiver executando um RDS multi-AZ, você não terá isso acontecer.