- You will be having a third party solution e.g. Dog Watch to monitor all your EC2 instances, and if there is any issue with the EC2 instance. It should be able to terminate the same.
- You will write a script which will continuously check the connection between EC2 instance and ELB. If connection is down it should be able terminate that instance and launch replacement for it.
- We will be setting up Auto Scaling group for web tier only and will be scaling based on the DB CPU utilization.
- Correct Answer
- We will do the vertical scaling by adding bigger instance for web tier.
- Correct Answer replica enabled.
Correct Answer : D, F
Detailed Explaination: In the given question we want that failover should be automatic or any other issue should be taken care automatically and must have as less manual intervention as possible.
There are two things which we need to take care
- EC2 instances: In this case we will have auto-scaling enabled. And whenever we see higher CPU utilization then launch new instance and if CPU utilization is reduced we should terminate the instance as well. So that we can save the cost.
- RDS instances: RDS instances are already setup for the read replica. Hence, provides the higher scalability for reading data. But in case of DB failure read replica does not automatically failover to read replica and required manual intervention to bring the DB up. However, it does not even create automatic backup of your DB.
We would need to setup Multi-Az for the primary DB. Hence, it can have more than one DB instances in two AZ one is primary and another is in standby mode. Hence, whenever primary DB fails it will automatically failover to the standby db.
You will keep the read replica setup so that read scalability available.