DOP-C02 Resilient Cloud Solutions Practice Test 4 — 15 Questions

Question 1

A company runs a critical application on Amazon RDS for MySQL with Multi-AZ deployment. The database is 2 TB in size. The DevOps team needs to perform a major version upgrade (e.g., MySQL 5.7 to 8.0) with minimal downtime. The RTO is 5 minutes and RPO is 1 minute. Which approach should the team take?

Choose an answer to begin — your selection is scored in the full session.

Accepted Answer

Create a read replica of the database in the same region, upgrade the replica to the new version, and then promote it to primary.. Creating a read replica, upgrading it to the new version, and then promoting it to primary is the best approach for minimizing downtime. The replica stays in sync with the primary, so when promoted, data loss is minimal (RPO near zero) and failover is fast (RTO within minutes). Option B (snapshot restore) has significant downtime because restoring and upgrading a snapshot takes time. Option C (in-place upgrade) causes downtime during the upgrade process, which can be lengthy for a 2 TB database. Option D (DMS) is more suited for heterogeneous migrations or ongoing replication, not a simple version upgrade, and would add complexity and potential downtime.

Answer

Take a snapshot of the database, restore it as a new instance, upgrade the restored instance, and redirect traffic.

Answer

Perform an in-place major version upgrade directly on the primary instance.

Answer

Use AWS Database Migration Service (DMS) to migrate data to a new database instance with the upgraded version.

Question 2

A financial services company runs a critical application on Amazon ECS with Fargate launch type. The application consists of three microservices: Service A (frontend), Service B (processing), and Service C (database access). Services communicate via REST APIs. The application stores data in Amazon Aurora PostgreSQL Serverless v2. The company has a disaster recovery (DR) requirement: RTO of 30 minutes and RPO of 15 minutes. The primary region is us-east-1 and the DR region is us-west-2. The DevOps team has configured cross-region replication for the Aurora database using an Aurora Global Database. The ECS services are deployed with a service-linked role for Fargate. The team wants to automate the failover process to meet the RTO. Which solution should the team implement?

Accepted Answer

Use AWS CloudFormation StackSets to deploy the ECS services and supporting resources in the DR region. Configure an Aurora Global Database for cross-region replication. Use Amazon Route 53 with health checks and failover routing to automatically redirect traffic to the DR region when the primary region health check fails.. The solution must meet RTO 30 min and RPO 15 min. Aurora Global Database provides cross-region replication with typical RPO of ~1 second and can be promoted in the secondary region in under a minute, satisfying RPO/RTO. CloudFormation StackSets deploys the ECS services and supporting resources in us-west-2, and Route 53 health checks with failover routing automatically redirect traffic when the primary fails — automating failover.

Answer

Take daily snapshots of the Aurora database and copy them to the DR region. In the event of a disaster, restore the snapshot and use AWS CloudFormation to launch the ECS services.

Answer

Use AWS Backup to schedule cross-region backups of the Aurora database every 15 minutes. In the event of a disaster, restore the latest backup and use Elastic Beanstalk to deploy the application in the DR region.

Answer

Configure AWS Global Accelerator with an endpoint group in each region. Use AWS Lambda to periodically check the health of the primary region and update the DNS records manually to point to the DR region.

Question 3

A company runs a critical application on AWS Lambda functions that process real-time streaming data from Amazon Kinesis Data Streams. Each Lambda function processes a batch of records and writes results to an Amazon DynamoDB table. The application is sensitive to data loss and requires exactly-once processing semantics. Recently, the operations team observed that the Lambda function is failing intermittently with 'ProvisionedThroughputExceededException' errors from DynamoDB. The Lambda function's batch size is 100, and the function is configured with a reserved concurrency of 500. The DynamoDB table has 100 read capacity units (RCUs) and 100 write capacity units (WCUs) with auto scaling enabled up to 1000 WCUs. The function's execution role has the necessary DynamoDB permissions. The Kinesis stream has 10 shards. The DevOps engineer needs to resolve the throttling errors without losing data. Which combination of actions should the engineer take? (Choose THREE.)

Accepted Answer

Set the Lambda function's batch size to a lower value (e.g., 10) and enable parallelization factor per shard.. Reducing the batch size decreases the number of records processed per invocation, lowering the write load on DynamoDB. Note that enabling the parallelization factor per shard increases the number of concurrent invocations per shard, which could actually increase write pressure; therefore, if used, it must be accompanied by sufficient write capacity. Option C is correct because configuring the event source mapping to retry failed records ensures that records are not lost; the Lambda function can retry after throttling errors, supporting exactly-once semantics. Option E is correct because increasing the DynamoDB table's maximum write capacity auto scaling limit allows the table to scale to higher WCUs during bursts, reducing ProvisionedThroughputExceededExceptions. Option B is incorrect because the error is due to write capacity, not read capacity; increasing RCUs does not help. Option D is incorrect because increasing reserved concurrency would increase the number of concurrent Lambda invocations, potentially increasing writes and worsening throttling.

Answer

Increase the DynamoDB table's read capacity units to 1000.

Answer

Increase the Lambda function's reserved concurrency to 1000.

Question 4

A company runs a containerized application on Amazon EKS. The application uses an Application Load Balancer (ALB) as the ingress controller. The DevOps team wants to ensure that the application can automatically recover from node failures. The cluster consists of managed node groups across three Availability Zones. The team noticed that when a node fails, the pods on that node are not rescheduled for several minutes. The team wants to reduce the time to reschedule pods. Which configuration change should the team make?

Accepted Answer

Configure the kubelet on the nodes to have a lower node-monitor-grace-period and pod-eviction-timeout.. Configuring the kubelet with a lower node-monitor-grace-period (e.g., 40 seconds) and pod-eviction-timeout reduces the time the control plane waits before marking the node as unhealthy and evicting pods, thereby speeding up pod rescheduling. Option A is incorrect because increasing pod disruption budgets actually delays voluntary disruptions but does not affect involuntary node failures. Option B is incorrect because the AWS node auto-repair feature (if available) is for automatically replacing unhealthy nodes, but it does not directly reduce the time to reschedule pods from a failing node; it may take additional time to launch a new node. Option C is incorrect because cluster autoscaler scales the cluster up by adding new nodes, but it does not accelerate the rescheduling of pods from an existing failed node; pod rescheduling depends on the kubelet's node-monitor-grace-period and pod-eviction-timeout.

Answer

Increase the pod disruption budget for the application deployments.

Answer

Enable the AWS node auto-repair feature on the managed node group.

Answer

Enable cluster autoscaler to add new nodes quickly.

Question 5

A company is deploying a critical web application on AWS and needs to ensure high availability and disaster recovery across multiple AWS Regions. The application uses an Application Load Balancer (ALB) in the primary Region and an Amazon RDS Multi-AZ DB instance. Which TWO actions should the company take to meet these requirements? (Choose two.)

Accepted Answer

Use AWS Global Accelerator with endpoint groups in multiple Regions.. Option D is correct because AWS Global Accelerator uses anycast IP addresses and endpoint groups in multiple Regions, allowing it to route traffic to the healthy ALB in the secondary Region when the primary Region fails, thereby providing cross-Region high availability and disaster recovery. Option E is correct because Amazon Route 53 failover routing with health checks monitors the primary ALB endpoint and automatically redirects DNS queries to the secondary Region's ALB when the primary becomes unhealthy, which is a standard multi-Region DR pattern. Option A is incorrect because RDS Multi-AZ is a single-Region feature that creates a standby in a different Availability Zone, not a secondary Region; cross-Region replication would require a read replica or Aurora Global Database. Option B is incorrect because CloudFront with multiple origins improves content delivery and can fail over between origins, but it does not by itself provide the required multi-Region application failover for the ALB and RDS architecture. Option C is incorrect because an Auto Scaling group in the secondary Region cannot automatically detect a primary Region failure and scale up on its own; failover must be driven by health checks and routing, and the group would also need to be running capacity to serve traffic.

Answer

Configure an Amazon RDS Multi-AZ deployment in a secondary Region.

Answer

Set up Amazon CloudFront with multiple origins pointing to each Region's ALB.

Answer

Create an Auto Scaling group in the secondary Region that automatically scales up when the primary fails.

Question 6

A company runs a critical web application on EC2 instances behind an Application Load Balancer. To improve resilience, they want to automatically replace unhealthy instances. Which AWS feature should they use?

Accepted Answer

Auto Scaling group with ELB health checks. Auto Scaling groups with ELB health checks automatically replace unhealthy instances by terminating and launching new ones. AWS Lambda functions can also be used to check health and launch new instances, providing a custom automation solution. Option A is the native recommended approach, while option C is a valid custom implementation. Option B is wrong because CloudWatch alarms can terminate instances but do not automatically launch replacements; Auto Scaling is needed. Option D is wrong because ELB health checks only mark instances unhealthy; they do not perform any replacement action.

Answer

CloudWatch alarm that terminates the instance

Answer

AWS Lambda function that checks health and launches new instances

Answer

Elastic Load Balancer health checks

Question 7

A company runs a global web application on EC2 instances behind an ALB in us-east-1. They want to improve resilience by routing users to the nearest healthy region. Which service should they use?

Accepted Answer

Amazon Route 53 latency-based routing with health checks. Amazon Route 53 latency-based routing with health checks directs users to the AWS region that provides the lowest latency while also monitoring the health of endpoints in each region. When combined with health checks, Route 53 can fail over to a healthy region if the primary region becomes unhealthy. This meets the requirement of routing users to the nearest healthy region for a global application.

Answer

AWS Global Accelerator

Answer

Application Load Balancer cross-zone load balancing

Answer

Amazon CloudFront with multiple origins

Question 8

Which THREE strategies can improve the resilience of an Amazon RDS for PostgreSQL database?

Accepted Answer

Enable automated backups with a retention period. Option B is correct because enabling automated backups with a retention period allows point-in-time recovery (PITR) to any second within the retention window (up to 35 days), protecting against data corruption or accidental deletion. Option C is correct because read replicas in another Availability Zone provide a standby copy that can be promoted to a primary during an AZ failure, improving availability and offloading read traffic. Option E is correct because Multi-AZ deployment maintains a synchronous standby replica in a different AZ with automatic failover, typically completing within 60–120 seconds, which directly enhances resilience. Option A is incorrect because disabling automated backups removes PITR capability and increases data-loss risk. Option D is incorrect because a single-AZ instance has no automatic failover and is vulnerable to AZ-level outages, reducing resilience.

Answer

Disable automated backups to save costs

Answer

Use a single-AZ instance to reduce complexity

Question 9

A company runs a containerized application on Amazon ECS with Fargate. The application experiences intermittent failures due to resource exhaustion. The company wants to improve resilience by automatically replacing unhealthy tasks and scaling based on demand. Which TWO actions should the company take? (Choose TWO.)

Accepted Answer

Define a health check command in the task definition to restart unhealthy containers.. Option C is correct because defining a health check command in the container definition lets ECS/Fargate detect an unhealthy container and automatically replace the task, directly improving resilience against intermittent failures. Option D is correct because ECS service auto scaling with a target tracking policy on CPU utilization adjusts the desired task count based on demand, which is the appropriate scaling mechanism for Fargate tasks. Option A is not correct because cluster auto scaling applies to EC2-backed clusters, not Fargate, which provisions capacity automatically. Option B is not correct because Auto Scaling groups manage EC2 instances, not ECS task counts. Option E is not correct because minimum healthy percent and maximum percent control deployment behavior during rolling updates, not ongoing health replacement or demand-based scaling.

Answer

Enable cluster auto scaling to add more Fargate capacity.

Answer

Use an Auto Scaling group to manage the number of tasks.

Answer

Set a minimum healthy percent of 50% and maximum percent of 200% in the service configuration.

Question 10

A company is running a stateful web application on EC2 instances behind an Application Load Balancer. During a deployment, users report session timeouts. What should the DevOps engineer implement to ensure zero-downtime deployments without losing in-flight sessions?

Accepted Answer

Enable connection draining (deregistration delay) on the ALB target group and use lifecycle hooks to wait for the draining period.. Connection draining (deregistration delay) on the ALB target group allows in-flight requests to complete before instances are deregistered, and lifecycle hooks can be used to wait for the draining period before terminating instances, ensuring zero-downtime deployments without losing in-flight sessions. Option A is incorrect because updating the launch template and performing a rolling update does not inherently handle in-flight sessions; session stickiness would still cause timeouts if instances are terminated abruptly. Option B is incorrect because using a lifecycle hook that waits for instance termination without connection draining does not ensure that existing sessions are completed. Option D is incorrect because increasing health check intervals and unhealthy thresholds only delays the detection of unhealthy instances but does not prevent session loss during deployments.

Answer

Update the Auto Scaling group's launch template to use a new AMI and perform a rolling update.

Answer

Use an Auto Scaling group with a lifecycle hook that waits for instance termination.

Answer

Increase the health check interval and unhealthy threshold on the ALB target group.

Question 11

A financial services company runs a multi-region application on AWS. They need to ensure that if one AWS Region becomes unavailable, traffic is automatically rerouted to another region with no manual intervention. The application uses an Application Load Balancer in each region. What is the MOST resilient approach to meet this requirement?

Accepted Answer

Use AWS Global Accelerator with endpoint groups in each region and health checks.. AWS Global Accelerator provides static anycast IP addresses and uses the AWS global network to route traffic to the optimal endpoint based on health, geography, and latency. With endpoint groups in multiple regions and health checks, it automatically fails over to a healthy region if one becomes unavailable, requiring no manual intervention. This meets the requirement for automatic multi-region failover with ALBs as endpoints.

Answer

Use Amazon CloudFront with origins in each region and configure origin failover.

Answer

Use a Network Load Balancer in each region and configure Route 53 with failover routing.

Answer

Use Route 53 with latency-based routing and health checks on the ALB endpoints.

Question 12

A DevOps engineer is designing a disaster recovery plan for a critical database. The RTO is 15 minutes and RPO is 1 minute. Which solution meets these requirements?

Accepted Answer

Use Amazon RDS Multi-AZ with automatic failover.. Amazon RDS Multi-AZ maintains a synchronous standby replica in a second Availability Zone with automatic failover, typically completing in 60–120 seconds — well within the 15-minute RTO. Because replication is synchronous, the RPO is effectively zero (no committed transaction loss), which satisfies the 1-minute RPO. This is the standard AWS-recommended solution for HA/DR within a Region.

Answer

Use Amazon RDS with cross-Region read replicas and promote one during failover.

Answer

Schedule automated snapshots every 1 minute and restore in the same AZ.

Answer

Deploy a standby EC2 instance with a self-managed replication script.

Question 13

A company uses AWS CloudFormation to deploy infrastructure. They want to ensure that if a stack update fails, the stack is automatically rolled back to the last known good state. However, they also want to preserve any resources that were created successfully before the failure. Which CloudFormation stack policy should be used?

Accepted Answer

Use a stack policy that allows all actions except delete.. A stack policy that denies delete actions prevents CloudFormation from deleting resources that were created successfully before failure during a rollback. When a stack update fails, CloudFormation rolls back to the previous state, which typically involves deleting or modifying resources that were created or modified during the failed update. By denying delete actions on specific resources, those resources are preserved even if the overall stack rolls back. Option B (deny update) is incorrect because denying update only prevents modifications, but resources can still be deleted during rollback. Option A is incorrect because a creation policy with a resource signal is used to control when instances are considered created, not for rollback preservation. Option D is incorrect because RollbackConfiguration with a monitoring time is used for rollout monitoring, not for preserving resources during rollback.

Answer

Define a creation policy with a resource signal.

Answer

Use a stack policy that denies update actions on resources that should be preserved.

Answer

Set the RollbackConfiguration property with a monitoring time.

Question 14

Which TWO actions can help protect against accidental deletion of an Amazon S3 bucket? (Select TWO.)

Accepted Answer

Enable MFA Delete on the bucket.. Options C (MFA Delete) and E (bucket policy denying s3:DeleteBucket) are correct. MFA Delete adds an extra layer of protection by requiring multi-factor authentication to permanently delete object versions and change the versioning state, which helps prevent accidental deletions. A bucket policy that explicitly denies the s3:DeleteBucket action directly prevents accidental bucket deletion. Option A is incorrect because versioning alone does not prevent bucket deletion; it protects object versions. Option B is incorrect because CloudTrail provides auditing of delete events but does not prevent them. Option D is incorrect because a lifecycle policy automatically deletes objects, increasing the risk of accidental deletion rather than protecting against it.

Answer

Enable versioning on the bucket.

Answer

Enable AWS CloudTrail to log delete events.

Answer

Configure a lifecycle policy to expire objects.

Question 15

A company's DevOps team is designing a multi-region disaster recovery solution for a stateless web application. The application runs on Amazon EC2 instances behind an Application Load Balancer (ALB) in the us-east-1 region. The team needs to fail over to a secondary region (us-west-2) with minimal downtime in case of a regional outage. Which AWS service should the team use to route traffic to the healthy region?

Accepted Answer

Amazon Route 53 with a failover routing policy and health checks on the primary ALB.. AWS Global Accelerator with endpoint groups in both regions automatically routes traffic based on health checks, allowing failover to the healthy region. The current explanation only justifies A and does not correctly dismiss C.

Answer

Elastic Load Balancing (ELB) cross-zone load balancing across regions.

Answer

Amazon CloudFront with a multi-origin setup and origin failover.