The reference architecture must meet the following requirements:• High availability within an AWS Region• Able to fail over in 1 minute to another AWS Region for disaster recovery• Provide the most efficient solution while minimizing the impact on the user experienceWhich combination of steps will meet these requirements?
(Choose three.)
Use an Amazon Route 53 weighted routing policy set to 100/0 across the two selected Regions. Set Time to Live (TTL) to 1 hour.
Use an Amazon Route 53 failover routing policy for failover from the primary Region to the disaster recovery Region. Set Time to Live (TTL) to 30 seconds.
Use a global table within Amazon DynamoDB so data can be accessed in the two selected Regions.
Back up data from an Amazon DynamoDB table in the primary Region every 60 minutes and then write the data to Amazon S3. Use S3 cross-Region replication to copy the data from the primary Region to the disaster recovery Region. Have a script import the data into DynamoDB in a disaster recovery scenario.
Implement a hot standby model using Auto Scaling groups for the web and application layers across multiple Availability Zones in the Regions. Use zonal Reserved Instances for the minimum number of servers and On-Demand Instances for any additional resources.
Use Auto Scaling groups for the web and application layers across multiple Availability Zones in the Regions. Use Spot Instances for the required resources.
Explanations:
Using a weighted routing policy does not provide immediate failover capabilities. A TTL of 1 hour is too long for disaster recovery, as it could significantly delay user requests during a failover event.
The failover routing policy with a TTL of 30 seconds allows for quick redirection of traffic to the disaster recovery Region, meeting the requirement for a 1-minute failover. This approach ensures that users experience minimal disruption.
Using a global table in Amazon DynamoDB ensures that data is automatically replicated across multiple Regions. This provides low-latency access and helps achieve high availability and disaster recovery across Regions.
While this option ensures data backup, it introduces complexity and latency due to the need for data import during a disaster recovery scenario. The 60-minute backup interval is also not aligned with the requirement for rapid failover.
Implementing a hot standby model with Auto Scaling groups ensures that there are always available resources in multiple Availability Zones. This setup supports high availability and allows for quick scaling in case of failure, meeting the disaster recovery requirement.
While Auto Scaling groups are essential for scaling resources, using Spot Instances introduces potential instability, as they can be terminated with little notice. This could negatively impact the user experience during a failover event.
From my perspective, the answer is:
Use an Amazon Route 53 failover routing policy for failover from the primary Region to the disaster recovery Region. Set Time to Live (TTL) to 30 seconds.