← DOP-C02·Amazon Web Services

Question 1,310 of 1,740

SDLC Automation →hardMultiple ChoiceObjective-mapped

Quick Answer

The answer is a database schema change by the new application version that broke the old version after rollback. This is correct because in a blue/green deployment, both the old and new task sets share the same database; if the new version applies a backward-incompatible schema migration—such as dropping a column or renaming a table—the old version’s code will fail when it tries to read or write using the old schema, causing it to become unhealthy even after the rollback restores the previous compute environment. On the AWS Certified DevOps Engineer Professional DOP-C02 exam, this scenario tests your understanding of stateful dependencies in immutable deployments, a common trap where candidates focus only on compute health checks and forget that shared resources like databases are not rolled back automatically. A useful memory tip is “schema first, code second”—always ensure database changes are backward-compatible or decouple schema migrations from the deployment pipeline to avoid corrupting the blue environment during a rollback.

DOP-C02 SDLC Automation Practice Question

This DOP-C02 practice question tests your understanding of sdlc automation. This is a configuration task: choose the command set that satisfies every stated requirement. Small differences — like 'secret' vs 'password' or 'transport input ssh' vs 'all' — change whether the answer is correct. After answering, compare your reasoning against the explanation and wrong-answer breakdown below. Once you have made your selection, read the full explanation to reinforce the concept and understand why each distractor is designed to mislead on exam day.

A company runs a critical application on Amazon ECS with Fargate. They use blue/green deployments via AWS CodeDeploy. During a recent deployment, the new task set failed health checks and CodeDeploy automatically rolled back. However, the old task set also became unhealthy shortly after rollback. What could explain this?

Question 1hardmultiple choice

Full question →

A
The CloudWatch alarm that triggered the rollback also stopped the old task set.
Why wrong: CloudWatch alarms do not stop tasks; they can trigger rollback but not stop old tasks.
B
CodeDeploy did not drain connections from the Application Load Balancer before terminating the old task set.
Why wrong: Connection draining is not directly related to health of old tasks after rollback.
C
The ECS service auto-scaling policy reduced the desired count of the old task set during the deployment.
Why wrong: Auto-scaling does not reduce count during blue/green deployment; CodeDeploy manages task sets.
D
The new application version changed the database schema, which broke the old version after rollback.
Database schema changes are not automatically rolled back, causing incompatibility.

Full breakdown with real-world context →

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

✓

The new application version changed the database schema, which broke the old version after rollback.

Option A is correct because a shared resource like a database schema change by the new version could corrupt data for the old version. Option B is wrong because CodeDeploy does not drain connections from ALB before rollback by default, but that would not cause the old version to become unhealthy. Option C is wrong because CloudWatch alarms are not configured by CodeDeploy to stop old tasks. Option D is wrong because ECS service auto-scaling does not stop tasks.

Key principle: NAT direction and interface roles matter as much as the IP address mapping. Inside/outside designation controls which traffic is translated.

Answer analysis

Option-by-option breakdown

For each option: why learners choose it and why it is or isn't the right answer here.

✗
The CloudWatch alarm that triggered the rollback also stopped the old task set.
Why it's wrong here
CloudWatch alarms do not stop tasks; they can trigger rollback but not stop old tasks.
✗
CodeDeploy did not drain connections from the Application Load Balancer before terminating the old task set.
Why it's wrong here
Connection draining is not directly related to health of old tasks after rollback.
✗
The ECS service auto-scaling policy reduced the desired count of the old task set during the deployment.
Why it's wrong here
Auto-scaling does not reduce count during blue/green deployment; CodeDeploy manages task sets.
✓
The new application version changed the database schema, which broke the old version after rollback.
Why this is correct
Database schema changes are not automatically rolled back, causing incompatibility.
Related concept
Static NAT maps one inside address to one outside address.

Common exam traps

Common exam trap: NAT rules depend on direction and matching traffic

NAT is not only about the public address. The inside/outside interface roles and the ACL or rule that matches traffic are just as important.

Detailed technical explanation

How to think about this question

NAT questions usually test address translation, overload/PAT behaviour, static mappings and whether the right traffic is being translated. Read the interface direction and address terms carefully.

KKey Concepts to Remember

Static NAT maps one inside address to one outside address.
PAT allows many inside hosts to share one public address using ports.
Inside local and inside global describe the private and translated addresses.
NAT ACLs identify traffic for translation, not always security filtering.

TExam Day Tips

Identify inside and outside interfaces first.
Check whether the scenario needs static NAT, dynamic NAT or PAT.
Do not confuse NAT matching ACLs with normal packet-filtering intent.

Key takeaway

NAT direction and interface roles matter as much as the IP address mapping. Inside/outside designation controls which traffic is translated.

Real-world example

How this comes up in practice

A cloud solutions architect for a retail company is evaluating services for a new workload. The correct answer here reflects best practice for the specific scenario described — not a general cloud recommendation. NAT direction and interface roles matter as much as the IP address mapping. Inside/outside designation controls which traffic is translated. Cloud exam questions reward reading the constraint carefully: the same technology can be right or wrong depending on the use case.

What to study next

Got this wrong? Here's your next step.

Review the four NAT address types (inside local, inside global, outside local, outside global), PAT port overload, and static vs dynamic NAT use cases. Then practise related DOP-C02 NAT questions on configuration and troubleshooting.

Related DOP-C02 practice-question pages

Use these pages to review the topic behind this question. This is how one missed question becomes focused revision.

Configuration Management and IaC practice questions

Practise DOP-C02 questions linked to Configuration Management and IaC.

Resilient Cloud Solutions practice questions

Practise DOP-C02 questions linked to Resilient Cloud Solutions.

Monitoring and Logging practice questions

Practise DOP-C02 questions linked to Monitoring and Logging.

Incident and Event Response practice questions

Practise DOP-C02 questions linked to Incident and Event Response.

Security and Compliance practice questions

Practise DOP-C02 questions linked to Security and Compliance.

SDLC Automation practice questions

Practise DOP-C02 questions linked to SDLC Automation.

DOP-C02 fundamentals practice questions

Practise DOP-C02 questions linked to DOP-C02 fundamentals.

DOP-C02 scenario practice questions

Practise DOP-C02 questions linked to DOP-C02 scenario.

DOP-C02 troubleshooting practice questions

Practise DOP-C02 questions linked to DOP-C02 troubleshooting.

Practice this exam

Start a free DOP-C02 practice session

Short sessions build daily habit. Longer sessions build exam-day stamina. Try a timed session to simulate real conditions.

10 questions 20 questions 30 questions 50 questions Timed 30

DOP-C02 practice-test guide →Study guide →Browse all practice tests

FAQ

Questions learners often ask

What does this DOP-C02 question test?

SDLC Automation — This question tests SDLC Automation — Static NAT maps one inside address to one outside address..

What is the correct answer to this question?

The correct answer is: The new application version changed the database schema, which broke the old version after rollback. — Option A is correct because a shared resource like a database schema change by the new version could corrupt data for the old version. Option B is wrong because CodeDeploy does not drain connections from ALB before rollback by default, but that would not cause the old version to become unhealthy. Option C is wrong because CloudWatch alarms are not configured by CodeDeploy to stop old tasks. Option D is wrong because ECS service auto-scaling does not stop tasks.

What should I do if I get this DOP-C02 question wrong?

What is the key concept behind this question?

Static NAT maps one inside address to one outside address.

About these practice questions

Courseiva creates original exam-style practice questions with explanations and wrong-answer analysis. It does not publish real exam questions, exam dumps, or protected exam content. Learn why practice questions differ from exam dumps →

How Courseiva writes practice questions · Editorial policy

Keep practising

Question Discussion

Share a tip, memory trick, or ask about the reasoning behind this question. Do not post real exam questions, leaked content, braindumps, or copyrighted exam material. Comments are moderated and may be removed without notice.

Loading comments…

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.