Recovery

Question 1

If you want to make sure your single non-distributed application can automatically recover from the failure of an AZ?

What values do you set for auto scaling group?

min?
max?
desired?

Answer 1

1
1
1

So we have an ASG with desired=1, across two AZ, so that if an instance goes down, it is automatically recreated in another AZ

Question 2

True or False

Elastic IP address, you can mask the failure of an instance or software by rapidly remapping the address to another instance in your account.

Answer 2

True

Question 3

Why would spot instances not work in this scenario?

You are deploying a critical monolith application that must be deployed on a single web server, as it hasn’t been created to work in distributed mode. Still, you want to make sure your setup can automatically recover from the failure of an AZ.

Answer 3

Spot instances can be terminated

Question 4

Why is using AWS Managed VPN as a backup for AWS Direct Connect connections to ensure maximum resiliency not a good idea?

Answer 4

AWS does not recommend customers use AWS Managed VPN as a backup for AWS Direct Connect connections with speeds greater than 1 Gbps.

Question 5

True or False, when rebalancing, EC2 auto scaling launches a new instance before terminating the old ones. And why?

Answer 5

True

so that rebalancing does not compromise the performance or availability of the application

Question 6

When removing unhealthy instances, does auto scaling group delete unhealthy instance first or provision new?

Answer 6

delete