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AWS Certified DevOps Engineer Professional DOP-C02 Practice Test

1,740 questions with instant explanations, domain breakdown, and wrong-answer analysis. Built for the real exam.

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Domain score breakdown
Real exam: 180 min
Pass mark: 750%

Sample questions with explanations

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Q1Incident and Event Responsemedium
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A company uses an Auto Scaling group with a dynamic scaling policy based on a custom CloudWatch metric. After a recent deployment, the metric spikes unexpectedly, causing the Auto Scaling group to launch several EC2 instances. The operations team wants to quickly determine whether the spike was caused by a real load increase or a deployment issue. What is the MOST efficient way to investigate this?

ACheck the SNS topic that the scaling policy publishes to for notifications.
Use CloudWatch Logs Insights to query application logs for error patterns or deployment markers that coincide with the metric spike.Correct
CUse AWS CloudTrail to review API calls that modified the scaling policy.
DTemporarily disable the scaling policy and manually increase the desired capacity to handle the load.

Option B is correct because CloudWatch Logs Insights allows you to query application logs for error patterns or deployment markers (e.g., new version tags, exception stack traces) that coincide with the metric spike. This directly correlates the scaling event with application-lev…Read full explanation

Q2Incident and Event Responsehard
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A company runs a critical application on Amazon ECS with Fargate launch type. The application uses an Application Load Balancer (ALB) in front. During a load test, the team notices a sudden increase in 5xx errors from the ALB, and some tasks become unhealthy. The task logs show occasional 'OutOfMemoryError' exceptions. The task definition currently has 512 CPU units and 1024 MiB memory. What should the team do to mitigate the issue while maintaining a cost-effective approach?

AIncrease the task definition CPU to 1024 units and memory to 2048 MiB.
Increase the task definition memory to 2048 MiB while keeping CPU at 512 units.Correct
CConfigure the ECS service to use a rolling update with a longer health check grace period.
DDecrease the task definition memory to 512 MiB to force garbage collection more frequently.

Option B is correct because the application is experiencing OutOfMemoryError, indicating the current 1024 MiB memory allocation is insufficient. Increasing memory to 2048 MiB while keeping CPU at 512 units directly resolves the memory constraint without unnecessary CPU cost. ECS …Read full explanation

Q3Incident and Event Responseeasy
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A DevOps engineer is investigating an incident where an EC2 instance became unreachable. The engineer checks the AWS Management Console and finds the instance is running, but the status check shows '2/2 checks passed' and the system log shows no errors. What should the engineer do NEXT to diagnose the connectivity issue?

AReview the CloudWatch metrics for CPU utilization and network throughput.
BReboot the instance to reset the network interface.
CStop and start the instance to move it to new underlying hardware.
Check the security group and network ACL rules to ensure inbound traffic is allowed.Correct

Since the instance is running, status checks pass, and the system log shows no errors, the issue is not with the operating system or underlying hardware. The most likely cause is a network-layer restriction, such as security group or network ACL rules blocking inbound traffic. Ch…Read full explanation

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