You are deploying a three-tier architecture in AWS. The web servers are going to reside in a private subnet, and the database and application servers are going to reside in a public subnet. You have chosen two AZs for high availability; thus, you are going to have two web servers, one in each AZ; two application servers, one in each AZ; and an RDS database in master standby mode where the standby database is running on a different AZ. In addition, you are using a NAT instance so that the application server and the database server can connect to the Internet if needed. You have two load balancers: one external load balancer connected to the web server and one internal load balancer connected to the application servers. What can you do to eliminate the single point of failure in this architecture?