Which of the below mentioned statements is helpful in this scenario?
Create VPC subnets in two separate availability zones and launch instances in different subnets.
Create VPC with only one public subnet and launch instances in different AZs using that subnet.
Create two VPCs in two separate zones and setup failover with ELB such that if one VPC fails it will divert traffic to another VPC.
Create VPC with only one private subnet and launch instances in different AZs using that subnet.
Explanations:
Creating VPC subnets in two separate availability zones (AZs) allows for high availability by ensuring that if one AZ fails, the instances in the other AZ can continue to operate. Launching instances in different subnets provides redundancy and fault tolerance.
Using only one public subnet for instances in multiple AZs does not enhance availability. If the single subnet encounters issues or if its AZ goes down, all instances would be affected, leading to a single point of failure.
Creating two VPCs in separate zones with ELB for failover is not a standard practice. VPCs cannot span multiple regions, and while failover is important, managing multiple VPCs adds complexity without significant benefits for high availability. A better approach is to utilize subnets within a single VPC across multiple AZs.
Using only one private subnet for instances in different AZs does not provide high availability. If the AZ hosting the private subnet fails, all instances would be affected, and there would be no redundancy. A private subnet should ideally be created in each AZ for resilience.