Centos 7 has Exim 4.84 in repos, which has DKIM support built-in. So no need for OpenDKIM anymore. See how is it configured:
If you have an autoscaling app on EC2, you need an ELB to distribute traffic. And if you don’t trust in ELB to be HA, you need at least 2 of them. The issue is that ELBs don’t have statis IPs, they can only be referenced with CNAME. That limits your DNS hosting option to just Route53, because apex record can’t be CN...
There’s still a shortage of proper Mysql proxy software. At the moment, there are 2 the most prominent: Mysqlproxy by Oracle and MaxScale by MariaDB. Seeing that there are no RPMs for Mysqlproxy, I decided to try out MaxScale first. Let’s see how it performed.