Would this cope with needing to replicate the web server onto another machine as well, for cloud-level reliability? Rather than web + local db <-----> rds

Would this cope with needing to replicate the web server onto another machine as well, for cloud-level reliability? Rather than web + local db <-----> rds you end up with web + local db <-\ |--> rds web + local db <-/ At which point the two masters plus a RDS slave is something I don't know if it's feasible.