Your company runs a customer facing event registration site This site is built with a 3-tier architecture with
web and application tier servers and a MySQL database The application requires 6 web tier servers and 6
application tier servers for normal operation, but can run on a minimum of 65% server capacity and a single
MySQL database. When deploying this application in a region with three availability zones (AZs) which
architecture provides high availability?
A.
A web tier deployed across 2 AZs with 3 EC2 (Elastic Compute Cloud) instances in each AZ inside an Auto
Scaling Group behind an ELB (elastic load balancer), and an application tier deployed across 2 AZs with 3 EC2
instances in each AZ inside an Auto Scaling Group behind an ELB. and one RDS (Relational Database Service)
instance deployed with read replicas in the other AZ.
B.
A web tier deployed across 3 AZs with 2 EC2 (Elastic Compute Cloud) instances in each A2 inside an Auto
Scaling Group behind an ELB (elastic load balancer) and an application tier deployed across 3 AZs with 2 EC2
instances in each AZ inside an Auto Scaling Group behind an ELB and one RDS (Relational Database Service)
Instance deployed with read replicas in the two other AZs.
C.
d A web tier deployed across 2 AZs with 3 EC2 (Elastic Compute Cloud) instances in each AZ inside an Auto
Scaling Group behind an ELB (elastic load balancer) and an application tier deployed across 2 AZs with 3 EC2
instances m each AZ inside an Auto Scaling Group behind an ELS and a Multi-AZ RDS (Relational Database
Service) deployment.
D.
A web tier deployed across 3 AZs with 2 EC2 (Elastic Compute Cloud) instances in each AZ Inside an Auto
Scaling Group behind an ELB (elastic load balancer). And an application tier deployed across 3 AZs with 2 EC2
instances In each AZ inside an Auto Scaling Group behind an ELB. And a Multi-AZ RDS (Relational Database
services) deployment.