DOP-C02 Practice Test 44 — 15 Questions

Question 1

A company uses AWS CodeDeploy to deploy applications to an Auto Scaling group. The deployment fails because the new version of the application crashes the instances. The DevOps engineer needs the Auto Scaling group to automatically replace the unhealthy instances with the previous working version. Which deployment configuration should the engineer use?

Accepted Answer

Blue/Green deployment with a load balancer to switch traffic only after health checks pass.. Option B (Blue/Green deployment) is correct because it keeps the old environment (blue) running while the new environment (green) is tested; if the green environment fails, traffic can be redirected back to blue. Option A is wrong because in-place deployments replace instances gradually and do not automatically revert. Option C is wrong because canary deployments are for gradual traffic shifting, not full rollback. Option D is wrong because linear deployments incrementally shift traffic and do not automatically roll back.

Answer

In-place deployment with a deployment group that has a failure threshold of 0.

Answer

Canary deployment that shifts 10% of traffic to the new version, then 100% after 10 minutes.

Answer

Linear deployment that shifts 10% of traffic every 10 minutes.

Question 2

A company runs a critical web application on AWS using an Application Load Balancer (ALB) in front of an Auto Scaling group of EC2 instances. The application experiences periodic traffic spikes. To handle these spikes, the company wants to use a combination of proactive scaling based on a predictable schedule and reactive scaling based on CPU utilization. What is the MOST resilient scaling strategy?

Accepted Answer

Use a scheduled scaling policy for the predictable spikes and a step scaling policy for CPU utilization.. Option B is correct because it combines scheduled scaling for predictable traffic with dynamic scaling for reactive adjustments, ensuring both proactive and reactive resilience. Option A is wrong because target tracking alone may not respond quickly to sudden spikes. Option C is wrong because predictive scaling requires historical data and may not be accurate for new patterns. Option D is wrong because manual scaling is not resilient for spikes.

Answer

Use predictive scaling based on historical traffic patterns.

Answer

Use manual scaling by increasing the desired capacity before expected spikes.

Answer

Use a target tracking scaling policy based on average CPU utilization.

Question 3

A company runs a critical application on AWS that uses an Auto Scaling group of EC2 instances. The application must remain available even if an entire Availability Zone fails. Which THREE actions should the company take?

Accepted Answer

Configure an ALB health check to automatically replace unhealthy instances.. Options A, B, and D are correct. Using multiple AZs ensures AZ failure tolerance; an ELB distributes traffic across AZs; an ALB health check ensures unhealthy instances are replaced. Option C is wrong because a single instance in each AZ is not resilient to AZ failure of one AZ. Option E is wrong because a single subnet per AZ is sufficient; multiple subnets per AZ are not required for resilience.

Answer

Use a single instance in each Availability Zone to minimize cost.

Answer

Use multiple subnets in each Availability Zone for the instances.

Question 4

A DevOps team uses AWS OpsWorks for configuration management. They have a stack with a custom cookbook that installs and configures an application. After updating the cookbook on GitHub, they need to apply the changes to existing instances without creating new ones. What should the team do?

Accepted Answer

Use the 'Execute Recipes' feature to run the updated custom recipe on the instances.. Option C (run a custom recipe using 'Execute Recipes' on the instances) is correct because it applies the updated cookbook without replacing instances. Option A is wrong because cloning creates a new stack, not updating existing instances. Option B is wrong because updating the stack configuration does not trigger cookbook execution. Option D is wrong because it updates the layer, but does not run the updated cookbook automatically.

Answer

Clone the stack and assign the updated cookbook to the new stack.

Answer

Update the layer's custom cookbook settings and then reboot the instances.

Answer

Update the stack's custom cookbook source and click 'Update Dependencies' on the stack.

Question 5

A company is designing a multi-region active-active architecture for a stateless web application. The application uses a DynamoDB table as its data store. The company wants to minimize write latency and ensure that writes are accepted in any region with eventual consistency. Which DynamoDB feature should they use?

Accepted Answer

DynamoDB global tables.. Option B is correct because DynamoDB global tables provide multi-region, multi-master replication for active-active applications. Option A is wrong because DynamoDB Accelerator (DAX) is a cache for read-heavy workloads, not multi-region writes. Option C is wrong because cross-region replication with Lambda is not built-in and adds complexity. Option D is wrong because read replicas do not accept writes.

Answer

DynamoDB read replicas in each region.

Answer

Cross-region replication using AWS Lambda function.

Answer

DynamoDB Accelerator (DAX) with multi-region endpoints.

Question 6

A company runs a microservices architecture on Amazon ECS with Fargate. Each service is deployed in its own ECS service. The company wants to ensure that if one Availability Zone (AZ) fails, the services can continue to operate with minimal impact. What is the MOST resilient task placement strategy?

Accepted Answer

Use a task placement strategy that spreads tasks across Availability Zones.. Option A is correct because setting spread across AZ ensures tasks are distributed evenly across AZs, and binpack with a spread across AZ is not possible; spread is the correct strategy. Option B is wrong because binpack does not guarantee AZ distribution. Option C is wrong because random may not distribute evenly. Option D is wrong because distinct instance is for EC2, not Fargate.

Answer

Use a task placement constraint to run tasks on distinct instances.

Answer

Use a task placement strategy that uses the random algorithm.

Answer

Use a task placement strategy that uses the binpack algorithm to maximize resource utilization.

Question 7

A company has a production RDS for PostgreSQL database. They need to perform a major version upgrade with minimal downtime. Which strategy provides the LEAST downtime while maintaining data integrity?

Accepted Answer

Create a read replica with the new engine version, promote it to a standalone database, and update the application connection string.. Option C is correct because creating a read replica with the new version, promoting it, and then switching DNS minimizes downtime. Option A is wrong because modifying the DB instance directly causes downtime. Option B is wrong because snapshot restore is time-consuming. Option D is wrong because DMS may have latency and data consistency issues.

Answer

Take a snapshot of the database and restore it as a new database with the new engine version.

Answer

Modify the existing DB instance and set the engine version to the new version.

Answer

Use the AWS Database Migration Service (DMS) to continuously replicate data to a new database with the new version.

Question 8

A company is designing a disaster recovery strategy for its on-premises database to AWS using AWS Elastic Disaster Recovery (AWS DRS). The recovery time objective (RTO) is 15 minutes, and the recovery point objective (RPO) is 1 minute. Which configuration should they use?

Accepted Answer

Configure AWS DRS to continuously replicate data to a staging area in AWS, and launch instances in the target region on failover.. Option A is correct because continuous replication with a staging area provides very low RPO. Option B is wrong because point-in-time restore from snapshots has higher RPO. Option C is wrong because CloudEndure (now AWS DRS) uses continuous replication. Option D is wrong because scheduled snapshots cannot achieve 1-minute RPO.

Answer

Use AWS CloudEndure Disaster Recovery (now AWS DRS) with periodic replication every hour.

Answer

Use AWS Backup to take snapshots every 5 minutes and restore in the target region.

Answer

Use RDS cross-region automated backups with a 5-minute backup window.

Question 9

A company runs a containerized application on Amazon EKS. They want to ensure that if a node fails, the pods are rescheduled on healthy nodes. Which configuration is necessary?

Accepted Answer

Configure the EKS managed node group with a health check and ensure that the Kubernetes control plane automatically reschedules pods from failed nodes.. Option A is correct because EKS manages node health and Kubernetes automatically reschedules pods from failed nodes. Option B is wrong because pod disruption budgets limit voluntary disruptions, not node failures. Option C is wrong because cluster autoscaler adds nodes, but does not reschedule pods from failed nodes. Option D is wrong because horizontal pod autoscaler scales pods based on load, not node failures.

Answer

Configure a pod disruption budget to prevent too many pods from being terminated simultaneously.

Answer

Use a horizontal pod autoscaler to increase the number of pods during high load.

Answer

Use a cluster autoscaler to automatically add new nodes when pods are pending.

Question 10

A company uses AWS CloudFormation to manage infrastructure. They have a template that creates an Amazon RDS DB instance. The template includes a 'DeletionPolicy' attribute set to 'Retain' on the DB instance resource. The DevOps team deletes the stack. Later, they notice that the DB instance still exists and is incurring costs. What is the MOST cost-effective way to remove the DB instance?

Accepted Answer

Manually delete the DB instance using the AWS Management Console or AWS CLI.. Option C (manually delete the DB instance via the AWS Management Console or CLI) is correct because the DeletionPolicy set to Retain prevents CloudFormation from deleting the resource; manual deletion is the simplest and cost-effective. Option A is wrong because updating the stack with deletion policy 'Delete' and then deleting again would work but is unnecessary extra steps. Option B is wrong because creating a new stack to delete the resource is overly complex. Option D is wrong because the RDS instance is not in a change set; it exists independently.

Answer

Create a new CloudFormation stack that includes the same DB instance but with a DeletionPolicy of 'Delete', then delete that stack.

Answer

Use the 'aws cloudformation delete-change-set' command to remove the resource.

Answer

Update the stack: change the DeletionPolicy to 'Delete' and then delete the stack again.

Question 11

A company runs a critical web application on Amazon EC2 instances behind an Application Load Balancer (ALB) across multiple Availability Zones. The application stores session data in a shared Amazon ElastiCache for Redis cluster. The operations team reports that during a recent AZ failure, users experienced session loss and application errors. Which combination of actions should the company take to improve resilience and maintain session state during an AZ failure? (Choose TWO.)

Accepted Answer

Configure the ALB with cross-zone load balancing enabled and connection draining set to a suitable timeout.. Option A is correct because enabling cross-zone load balancing on the ALB ensures traffic is distributed evenly across all EC2 instances in all AZs, and connection draining with a suitable timeout allows in-flight requests to complete before instances are deregistered, preventing session loss during an AZ failure. Option C is correct because enabling cluster mode for ElastiCache for Redis with replica nodes in different AZs provides automatic sharding and replication, ensuring session data remains available and consistent even if a primary node in one AZ fails.

Answer

Deploy an Auto Scaling group with a dynamic scaling policy that adds instances in the remaining AZs.

Answer

Configure the application to use a custom DNS name with a low TTL pointing to the ElastiCache cluster endpoint.

Answer

Enable Multi-AZ for the ElastiCache cluster to automatically fail over to a replica in another AZ.

Question 12

A company is using AWS CloudTrail to log API activity in their AWS account. They want to ensure that any modification to CloudTrail configuration itself is logged and that the logs are immutable. Which combination of actions should they take? (Choose TWO.)

Accepted Answer

Enable S3 Object Lock on the destination S3 bucket in governance mode.. Option A is correct because enabling S3 Object Lock in governance mode on the destination S3 bucket prevents any user, including the root user, from overwriting or deleting CloudTrail log objects during the retention period, ensuring immutability. Option B is correct because enabling log file validation creates a digest file that uses SHA-256 hashing to verify that log files have not been modified, deleted, or tampered with after delivery, providing integrity assurance.

Answer

Disable log file validation to reduce overhead.

Answer

Store CloudTrail logs in a CloudWatch Logs log group with a retention policy.

Answer

Enable CloudTrail Insights to detect configuration changes.

Question 13

A company runs a web application on EC2 instances behind an ALB. To improve resilience, they want to automatically re-register failed instances. Which solution meets this requirement?

Accepted Answer

Enable EC2 instance recovery and configure ALB health checks to deregister unhealthy instances.. Option C is correct because an ALB health check failure triggers deregistration and, with instance recovery, the instance is replaced and re-registered. Option A is wrong because Auto Scaling launches new instances but doesn't automatically re-register failed ones without a scaling policy. Option B is wrong because Route 53 health checks don't manage instance registration with ALB. Option D is wrong because CloudWatch does not directly re-register instances.

Answer

Set up a CloudWatch alarm to terminate the instance and notify an operator to re-register it.

Answer

Configure Auto Scaling to launch a new instance on instance failure.

Answer

Use Route 53 health checks to detect failure and update DNS to remove the instance.

Question 14

A company uses DynamoDB global tables with two regions. They notice that writes in one region are not replicating to the other region after a brief network partition. Which configuration will ensure replication resumes automatically?

Accepted Answer

No action needed; DynamoDB automatically resumes replication when connectivity is restored.. Option B is correct because DynamoDB global tables automatically resume replication after a partition is resolved. Option A is incorrect because there is no failover needed; replication is handled automatically. Option C is incorrect because disabling and re-enabling global tables would cause data loss. Option D is incorrect because the issue is not a conflict but a temporary partition.

Answer

Use DynamoDB Streams with a Lambda function to manually replicate writes.

Answer

Manually fail over the table to the other region.

Answer

Delete the replica table and recreate it.

Question 15

A company wants to ensure its RDS Multi-AZ deployment automatically fails over to a standby instance in a different Availability Zone. Which additional step is required?

Accepted Answer

No additional step; RDS Multi-AZ handles automatic failover.. Option A is correct because RDS Multi-AZ automatically fails over to the standby when the primary becomes unhealthy. Option B is incorrect because a read replica is for read scaling, not automatic failover. Option C is incorrect because RDS handles DNS changes automatically. Option D is incorrect because Multi-AZ does not require a different VPC.

Answer

Create an Amazon Route 53 health check to update the DNS record.

Answer

Configure a read replica in another AZ.

Answer

Deploy the standby instance in a different VPC.