AZ-400 Practice Test 25 — 15 Questions

Question 1

You are designing a release pipeline for a critical application that must minimize downtime during deployment. The application runs on Azure Kubernetes Service (AKS) and uses Azure SQL Database. Which deployment strategy should you recommend?

Accepted Answer

Blue-green deployment with traffic manager.. Option B is correct because blue-green deployment allows you to deploy a new version (green) alongside the old (blue) and switch traffic after validation, minimizing downtime. Option A (rolling update) gradually replaces pods but can cause downtime if the new version is broken. Option C (canary) only routes a small percentage of traffic, which is good for testing but not for minimizing downtime for the entire app. Option D (recreate) causes full downtime.

Answer

Rolling update with health probes.

Answer

Canary deployment with progressive exposure.

Answer

Recreate deployment by deleting the old version first.

Question 2

Your organization uses GitHub for source control and Azure Pipelines for CI/CD. You need to implement a policy that requires all pull requests to be built and pass tests before merging. What should you do?

Accepted Answer

Add a branch protection rule in the GitHub repository requiring status checks.. Option B is correct because branch protection rules in GitHub can require status checks to pass. Option A is wrong because pipeline permissions don't enforce PR checks. Option C is wrong because trigger controls build triggers, not merge requirements. Option D is wrong because environment checks are for deployments.

Answer

Set the pipeline trigger to run on pull request.

Answer

Configure pipeline permissions to require approval.

Answer

Add a pre-deployment check on the environment.

Question 3

Your organization uses GitHub Actions with self-hosted runners on Azure virtual machines. You notice that some workflows are taking longer than expected because runners are busy. You need to improve the performance without adding more permanent runners. Which solution should you implement?

Accepted Answer

Implement auto-scaling for self-hosted runners using a scale set or Kubernetes-based runner controller.. GitHub Actions supports auto-scaling for self-hosted runners using scaling applications like 'actions-runner-controller' for Kubernetes or custom scripts. Option A is correct because it dynamically adds/removes runners based on demand. Option B increases cost and maintenance. Option C is for GitHub-hosted runners. Option D reduces wait but doesn't address root cause.

Answer

Migrate all workflows to GitHub-hosted runners.

Answer

Reduce the number of concurrent jobs in each workflow.

Answer

Increase the size of the existing self-hosted runner VMs to handle more jobs.

Question 4

You are designing a release pipeline for a critical production application. The pipeline must ensure that changes are deployed to a staging environment first, and if integration tests pass, they are automatically deployed to production. However, if the tests fail, the deployment to production must be blocked. What is the best approach?

Accepted Answer

Create a multi-stage YAML pipeline with a gate on the production stage that evaluates test results from the staging stage.. A multi-stage YAML pipeline with a gate on the production stage that evaluates test results is the best approach because it allows for automated promotion with conditional logic. Option A is wrong because a single stage with conditional tasks doesn't separate environments properly. Option B is wrong because separate pipelines are harder to manage and coordinate. Option D is wrong because manual approval defeats the requirement for automatic deployment.

Answer

Create a single stage in the pipeline with conditional tasks to deploy to staging and then to production based on test results.

Answer

Create two separate pipelines: one for staging and one for production. Use a pipeline trigger to run the production pipeline after staging completes.

Answer

Use a classic release pipeline with pre-deployment approvals on the production stage.

Question 5

Which THREE are valid ways to trigger a pipeline in Azure Pipelines using GitHub integration? (Choose three.)

Accepted Answer

GitHub App webhooks. GitHub branch push triggers, pull request triggers, and GitHub App webhooks are valid methods. Option B is wrong because Azure Pipelines does not support direct polling of GitHub. Option E is wrong because schedule triggers are not GitHub-specific.

Answer

Polling GitHub on a schedule

Answer

Azure Pipelines schedule trigger

Question 6

Your Azure DevOps pipeline uses the 'DotNetCoreCLI@2' task to run unit tests. Some tests are failing intermittently. You suspect test flakiness due to race conditions. What should you do to automatically retry failed tests without rewriting the tests?

Accepted Answer

Use the 'VSTest@2' task with 'retryFailedTests: true' option.. Option B is correct because the 'retryFailedTests' option in the VSTest task automatically retries failed tests. Option A is a workaround but not a built-in feature. Option C requires custom scripting. Option D is not available in Azure DevOps.

Answer

Create a custom script that runs each test individually and retries on failure.

Answer

Enable 'test retry' in the pipeline settings under 'General'.

Answer

Wrap the test task in a 'Retry' loop using a 'each' expression.

Question 7

Your Azure DevOps pipeline deploys to multiple environments (Dev, Test, Prod) using YAML multi-stage pipelines. The Prod deployment requires manual approval. However, the approval gate shows 'Pending' even after an authorized user approves. What is the most likely cause?

Accepted Answer

The approval gate is configured to require approval on the latest commit, but a newer commit was pushed after the approval.. Option D is correct because branch policy requires the approval to be on the specific commit that triggered the release. Option A is wrong because re-running does not change the commit. Option B is wrong because the policy is not about the build but the commit. Option C is wrong because the user is authorized.

Answer

The pipeline run was triggered by a PR merge, and the approval needs to be re-applied after the build completes.

Answer

The build pipeline includes a step that modifies the approval settings.

Answer

The approver is not a member of the security group defined in the approval settings.

Question 8

Your organization uses Azure Pipelines to deploy a web application to multiple Azure App Service instances across regions. You need to implement a deployment strategy that allows rolling back to the previous version quickly if issues are detected. Which TWO strategies should you recommend?

Accepted Answer

Use blue-green deployment with a traffic manager endpoint.. Option A and Option D are correct. Slot swap allows swapping back to the previous slot. Blue-green deployment with a traffic manager allows switching traffic. Option B is wrong because redeployment takes time. Option C is wrong because canary is for gradual rollout, not instant rollback. Option E is wrong because it doesn't address rollback.

Answer

Use a rolling update with incremental deployment.

Answer

Implement a canary deployment with traffic splitting.

Answer

Store previous deployment artifacts in Azure Blob Storage.

Question 9

You have the YAML pipeline snippet shown in the exhibit. The first run produces version 1.0.0. What will be the version produced on the third run?

Accepted Answer

1.0.2. Option C is correct because the counter expression starts at 0 for majorVersion=1 and increments each run. First run: 0, second: 1, third: 2. Option A is wrong because counter does not reset. Option B is wrong because it is the first run value. Option D is wrong because counter increments by 1 each run, not by 2.

Answer

1.0.1

Answer

1.0.3

Answer

1.0.0

Question 10

You need to implement a build retention policy that automatically deletes old builds after 30 days, but keeps the latest 5 builds regardless of age. Which configuration should you use?

Accepted Answer

Set 'Days to keep builds' to 30 and 'Minimum number of builds to keep' to 5. Option A is correct because in Azure Pipelines retention policy, you set 'Days to keep builds' to 30 and 'Minimum number of builds to keep' to 5. Option B is wrong because 'Maximum retention policy' is not a setting. Option C is wrong because 'Number of days to keep artifacts' is separate from builds. Option D is wrong because 'Number of days to keep runs' is for GitHub Actions.

Answer

Set 'Number of days to keep runs' to 30 and 'Number of runs to keep' to 5

Answer

Set 'Maximum retention policy' to 30 days and 'Number of builds to retain' to 5

Answer

Set 'Number of days to keep artifacts' to 30 and 'Number of artifacts to keep' to 5

Question 11

You run the above KQL query in Log Analytics to troubleshoot a failing container in a Kubernetes deployment. The query returns no results even though you know there are errors. What is the most likely cause?

Accepted Answer

Container logs are not being sent to the ContainerLog table.. Option D is correct because container logs may be sent to a different table (e.g., ContainerLogV2) or the log collection is not configured. Option A is wrong because the query is correct syntax. Option B is wrong because 'contains' is case-insensitive. Option C is wrong because the query returns only three columns, not affecting results.

Answer

The 'project' clause filters out relevant rows.

Answer

The 'contains' operator is case-sensitive.

Answer

The KQL syntax is incorrect.

Question 12

You have a YAML pipeline that builds a Java project using Maven. The pipeline uses a private artifact feed in Azure Artifacts. You need to authenticate to the feed from the pipeline. Which authentication method should you use?

Accepted Answer

Use the 'MavenAuthenticate' task with a settings.xml file.. Azure Pipelines can use the project-level 'Azure Artifacts' service connection to authenticate to feeds. Option B is correct because it uses the pipeline identity. Option A is for npm. Option C is for Python. Option D is for NuGet.

Answer

Use the 'PipAuthenticate' task with a pip.conf file.

Answer

Use the 'npmAuthenticate' task with a .npmrc file.

Answer

Use the 'NuGetAuthenticate' task with a nuget.config file.

Question 13

Which TWO features in Azure Pipelines allow you to enforce separation of duties between development and operations teams? (Choose two.)

Accepted Answer

Approvals and checks on environments. Approvals and checks enforce separation by requiring ops approval before deployment. Environment security ensures only specific users can deploy to production. Option C is wrong because branch policies are for source control, not deployment. Option D is wrong because service connections are for authentication, not separation of duties. Option E is wrong because pipeline decorators inject steps but do not enforce separation.

Answer

Pipeline decorators

Answer

Service connections with different scopes

Answer

Branch policies on the main branch

Question 14

You need to automatically run a pipeline when a new tag is pushed to the repository. Which trigger configuration should you use?

Accepted Answer

Tags trigger. Tags trigger allows running pipelines on tag creation or update. Option B is wrong because CI trigger is for branches. Option C is wrong because PR trigger is for pull requests. Option D is wrong because schedule trigger is time-based.

Answer

Schedule trigger

Answer

PR trigger

Answer

CI trigger with branch filters

Question 15

You are implementing a CI pipeline for a Node.js application. The pipeline must run linting, unit tests, and build the application. Which YAML structure is most appropriate?

Accepted Answer

Define one job with multiple steps: lint, test, build.. Option B is correct because jobs allow multiple steps to run sequentially on the same agent, which is efficient for linting, testing, and building. Option A uses stages but not necessary. Option C runs steps in parallel, which may cause conflicts. Option D is not valid YAML for Azure Pipelines.

Answer

Define three separate stages: lint, test, build.

Answer

Define one job with parallel steps using 'parallel' keyword.

Answer

Define multiple jobs without dependencies.