Designing Cross-Region DR for EC2 and RDS with RPO 15 min, RTO 1 hour
A company is designing a disaster recovery plan for a critical application with an RPO of 15 minutes and RTO of 1 hour. The application runs on EC2 instances with an RDS MySQL database. The primary Region is us-east-1. Which THREE actions should they take to meet the RPO and RTO? (Choose three.)
Quick Answer
The answer is to create a cross-Region read replica of the RDS MySQL database in us-west-2, enable automated AMI backups of the EC2 instances every 15 minutes, and pre-stage the infrastructure in the secondary Region. This combination meets the 15-minute RPO because the RDS read replica provides near-synchronous replication with minimal data loss, while the 15-minute AMI snapshots capture EC2 volume changes within that window. For the 1-hour RTO, pre-staging the network, security groups, and Auto Scaling groups in us-west-2 allows rapid failover by promoting the read replica to a standalone database and launching EC2 instances from the latest AMI. On the AWS DevOps Engineer Professional exam, this scenario tests your ability to balance cost and complexity against strict recovery objectives—a common trap is assuming multi-AZ alone suffices for cross-Region DR, but it only covers within-Region failover. Remember the mnemonic: “Read replicas for RDS, AMIs for EC2, and pre-stage to save the day.”
⚠ Common exam trap
It's easy for candidates to confuse infrastructure-as-code deployment (CloudFormation StackSets) with actual data replication, mistakenly believing that deploying identical infrastructure alone satisfies the RPO, when in fact continuous database replication is required to meet the 15-minute RPO.
Answer choices
Why each option matters
Answer the question above first, then reveal the full breakdown to understand why each option is right or wrong.
Correct answer & explanation
✓
Schedule automated AMI backups of EC2 instances every 15 minutes
Automated AMI backups of EC2 instances every 15 minutes align with the 15-minute RPO by capturing incremental snapshots of the instance volumes. These AMIs can be used to launch replacement EC2 instances in the secondary Region within the 1-hour RTO, provided the infrastructure is pre-staged. The frequency of 15 minutes ensures that data loss is limited to at most 15 minutes of changes.
Answer analysis
Option-by-option breakdown
For each option: why learners choose it and why it is or isn't the right answer here.
- ✓
Schedule automated AMI backups of EC2 instances every 15 minutes
Why this is correct
Quick recovery of EC2 instances.
- ✗
Launch EC2 instances in a single Availability Zone in the secondary Region to reduce costs
Why it's wrong here
Single AZ is not fault-tolerant.
- ✓
Configure Route 53 health checks and DNS failover to the secondary Region
Why this is correct
Automates traffic redirection.
- ✓
Create a cross-Region read replica of the RDS MySQL database in us-west-2
Why this is correct
Provides near real-time replication for RPO.
- ✗
Use AWS CloudFormation StackSets to deploy identical infrastructure in the secondary Region
Why it's wrong here
Infrastructure deployment does not replicate data.
Go deeper
Related to this question
About these practice questions
One of 251 original DOP-C02 practice questions on Courseiva, each with a full explanation and wrong-answer analysis — not exam dumps or protected exam content. Learn why practice questions differ from exam dumps →
Same concept, more angles
3 more ways this is tested on DOP-C02
These questions test the same concept from different angles. Work through them to make sure you can recognise it however the exam phrases it.
Variation 1. A company is designing a disaster recovery plan for a critical application that uses Amazon RDS for MySQL with Multi-AZ. The RPO must be less than 1 minute and RTO less than 15 minutes. The primary Region is us-east-1. Which TWO steps should the company take to meet these requirements?
hard- A.Take manual snapshots of the RDS instance every 30 seconds and copy them to the secondary Region
- B.Enable Multi-AZ in the primary Region
- ✓ C.Create a cross-Region read replica of the RDS instance in the secondary Region
- ✓ D.Create an AWS Lambda function to promote the read replica to primary in the secondary Region during a disaster
- E.Enable automated backups with cross-Region copy enabled to the secondary Region
Why C: C and D are correct. A cross-Region read replica of the RDS instance in the secondary Region provides near-real-time replication, achieving an RPO of less than 1 minute. When a disaster occurs, the read replica can be promoted to a primary instance quickly, meeting the RTO of less than 15 minutes. An AWS Lambda function can automate the promotion process, reducing manual intervention and further improving RTO. Option E is incorrect because automated backups with cross-Region copy are taken periodically (e.g., daily), not continuously, so they cannot achieve an RPO of less than 1 minute.
Variation 2. A company is designing a disaster recovery (DR) strategy for a critical application that runs on EC2 instances with an RDS database. The DR site must be in a different AWS Region. The Recovery Point Objective (RPO) is 15 minutes, and Recovery Time Objective (RTO) is 1 hour. Which TWO actions should the company take to meet these objectives? (Choose TWO.)
medium- A.Use AWS Backup to copy EC2 AMIs and RDS snapshots to the DR region every 15 minutes.
- B.Use AWS CloudFormation to pre-provision resources in the DR region manually.
- ✓ C.Configure Amazon Route 53 with health checks and failover routing to the DR region.
- ✓ D.Create an RDS cross-Region read replica in the DR region.
- E.Configure S3 cross-Region replication for application data stored in S3.
Why C: Options C and D are correct. D: Creating an RDS cross-Region read replica in the DR region allows the replica to be promoted to the primary database with minimal data loss, meeting the 15-minute RPO. C: Configuring Amazon Route 53 with health checks and failover routing enables automatic traffic redirection to the DR region within the 1-hour RTO. Option A is wrong because copying AMIs and RDS snapshots every 15 minutes would require launching EC2 instances and restoring the database from snapshots, which can exceed the 1-hour RTO. Option B is wrong because manually pre-provisioning resources with CloudFormation does not provide the automated failover needed to meet the RTO. Option E is wrong because S3 cross-Region replication does not address the EC2 and RDS components of the application.
Variation 3. A company is designing a disaster recovery strategy for a critical application that requires a Recovery Time Objective (RTO) of 15 minutes and a Recovery Point Objective (RPO) of 1 hour. The application runs on EC2 with data stored in Amazon RDS Multi-AZ. Which approach meets these requirements?
medium- ✓ A.Use a pilot light strategy with RDS cross-Region read replicas and automated backups
- B.Use backup and restore with daily snapshots to another Region
- C.Use a warm standby with a scaled-down production environment in another Region
- D.Use a Multi-AZ deployment in the same Region for DR
Why A: A pilot light strategy with RDS cross-Region read replicas and automated backups meets the RTO of 15 minutes and RPO of 1 hour. The cross-Region read replica provides near-synchronous replication with an RPO typically under 5 seconds, and automated backups enable point-in-time recovery within the 1-hour RPO. The pilot light approach allows rapid promotion of the replica to a primary instance, achieving the 15-minute RTO by keeping minimal core services running in the DR Region.
JA
Written by Johnson Ajibi, MSc IT Security
Senior Network & Security Engineer · founder of Courseiva
This DOP-C02 practice question is part of Courseiva's free Amazon Web Services certification practice question bank. Courseiva provides original exam-style practice questions with explanations, topic-based practice, mock exams, readiness tracking, and study analytics to help learners prepare for the DOP-C02 exam.