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Practice Exam
Question 1. In Cloud Foundry, which service model provides the highest level of abstraction for developers? A) IaaS B) PaaS C) SaaS D) FaaS Answer: B Explanation: PaaS (Platform as a Service) abstracts infrastructure (IaaS) and offers a complete runtime environment, allowing developers to focus on code without managing servers. Question 2. Which component is responsible for routing incoming HTTP requests to the appropriate application instances? A) Cloud Controller B) Diego Cell C) Gorouter D) Loggregator Answer: C Explanation: The Gorouter receives external traffic and forwards it to the correct app instances based on route mappings. Question 3. The Cloud Controller primarily handles which of the following tasks? A) Log aggregation B) Application health checks C) Managing app lifecycle metadata D) Container networking Answer: C
Practice Exam
Explanation: The Cloud Controller stores and manages metadata about apps, orgs, spaces, and user permissions; it orchestrates actions like push, start, stop. Question 4. Which CLI command sets the target organization and space for subsequent cf commands? A) cf login B) cf target C) cf set-org D) cf use-space Answer: B Explanation: cf target - o ORG - s SPACE configures the CLI’s current context, affecting all later commands. Question 5. The environment variable VCAP_SERVICES contains what type of information? A) Application route URLs B) Bound service credentials and metadata C) Memory and disk limits for the app D) User authentication tokens Answer: B Explanation: VCAP_SERVICES is a JSON payload injected into the app that lists all bound services and their credentials. Question 6. During a cf push, what is the purpose of the staging phase? A) Allocating network ports B) Compiling the app and creating a droplet C) Starting the app instances
Practice Exam
A) cf restart-app-instance B) cf restart C) cf restage D) cf start --restart Answer: B Explanation: cf restart APP stops and then starts the app using the existing droplet; cf restage would rebuild the droplet. Question 10. In a manifest.yml file, which key defines the amount of memory allocated to each app instance? A) instances B) memory C) disk_quota D) buildpack Answer: B Explanation: The memory field specifies the memory limit per instance (e.g., 512M). Question 11. Which command lists all services available in the marketplace? A) cf services B) cf marketplace C) cf service-brokers D) cf service-access Answer: B Explanation: cf marketplace shows the catalog of service offerings that can be provisioned.
Practice Exam
Question 12. When creating a user‑provided service instance (UPSI), which flag supplies the credentials JSON? A) --credentials B) - c C) --param-json D) - p Answer: B Explanation: cf create-user-provided-service SERVICE_NAME - c '{"uri":"..."}' uses the -c flag to pass a credentials map. Question 13. A service key is primarily used for which purpose? A) Binding a service to an app automatically B) Providing out‑of‑band access credentials to a service C) Deleting a service instance remotely D) Scaling the service horizontally Answer: B Explanation: Service keys generate credentials that external systems can use to access the service without a CF app binding. Question 14. What is the role of an Open Service Broker in Cloud Foundry? A) It routes HTTP traffic to apps B) It supplies the buildpacks for staging C) It implements the Service Broker API to expose services to the marketplace D) It monitors application health Answer: C
Practice Exam
Answer: B Explanation: By mapping the new (“green”) app to the route while the old (“blue”) app remains running, traffic is switched instantly, eliminating downtime. Question 18. Container‑to‑Container (C2C) networking enables: A) Direct TCP connections between app instances without leaving the Diego cell network B) Automatic load balancing across different organizations C) Public internet access for containers D) Persistent storage sharing between containers Answer: A Explanation: C2C networking provides an internal overlay network so app instances can communicate via internal IPs. Question 19. Which cf command creates a TCP route for an app that does not use HTTP? A) cf map-route APP DOMAIN --port PORT B) cf create-tcp-route DOMAIN --port PORT C) cf map-tcp-route APP DOMAIN --port PORT D) cf bind-tcp-route APP DOMAIN --port PORT Answer: C Explanation: cf map-tcp-route APP DOMAIN --port PORT assigns a TCP route to the app. Question 20. Horizontal scaling of an application is achieved by: A) Increasing the memory limit per instance B) Adding more instances of the app C) Changing the buildpack version
Practice Exam
D) Modifying the app’s Docker image size Answer: B Explanation: Horizontal scaling adds parallel instances to handle more concurrent requests. Question 21. To adjust the memory quota of a single instance without changing the number of instances, which command is used? A) cf scale APP - m 1G B) cf resize APP - m 1G C) cf set-memory APP 1G D) cf update-app APP - m 1G Answer: A Explanation: cf scale APP - m 1G changes the memory per instance while leaving the instance count unchanged. Question 22. The Application Autoscaler in Cloud Foundry reacts to which metric by default? A) Disk I/O B) Network latency C) CPU usage D) Number of bound services Answer: C Explanation: The default autoscaler policy can be set to trigger on CPU, memory, or request throughput; CPU is the most common default. Question 23. High availability in Cloud Foundry is primarily ensured by: A) Running the Gorouter in multiple zones
Practice Exam
A) Forward application logs to an external logging service via syslog protocol B) Store logs locally on the Diego cell for later retrieval C) Encrypt logs before sending them to the Loggregator D) Delete logs after a configurable retention period Answer: A Explanation: A syslog drain sends logs out of CF to any syslog endpoint (e.g., Splunk, ELK). Question 27. The cf events APP command displays: A) All HTTP requests received by the app B) Historical lifecycle events such as starts, stops, crashes, and scaling actions C) Real‑time CPU and memory metrics D) Service binding changes only Answer: B Explanation: cf events shows a timeline of platform‑generated events for the app. Question 28. Which cf subcommand provides an interactive SSH session into a running app container? A) cf ssh APP B) cf console APP C) cf remote-login APP D) cf exec APP Answer: A Explanation: cf ssh opens a secure shell to the container, allowing debugging. Question 29. During staging, a buildpack failure is most likely caused by:
Practice Exam
A) Insufficient disk quota on the Diego cell B) Missing required runtime environment variables C) Incompatible operating system version on the cell D) An error in the buildpack’s compile script Answer: D Explanation: Buildpack failures usually arise from errors in detection, compilation, or packaging scripts. Question 30. Which role can create and delete spaces within an organization? A) Org Auditor B) Org Manager C) Space Developer D) Space Auditor Answer: B Explanation: Org Managers have permissions to manage org‑level resources, including spaces. Question 31. Application Security Groups (ASGs) are used to control: A) Inbound traffic from the internet to apps B) Outbound egress traffic from app containers C) Access to the Cloud Controller API D) Permissions for service binding Answer: B Explanation: ASGs define egress rules (e.g., allow DNS, HTTP) for app containers. Question 32. The UAA component in Cloud Foundry is responsible for:
Practice Exam
Explanation: Stateless apps keep no mutable state locally; any needed state is externalized (e.g., databases, caches). Question 35. To ensure portability of an app across different Cloud Foundry installations, you should avoid: A) Using buildpacks that are standard across CF B) Hard‑coding absolute file system paths C) Declaring memory limits in the manifest D) Binding services via VCAP_SERVICES Answer: B Explanation: Hard‑coded file paths tie the app to a specific environment, breaking portability. Question 36. In Cloud Foundry, a “droplet” refers to: A) The compiled and packaged version of the app ready for execution B) The network route assigned to the app C) The log file buffer for the app D) The Docker image used by the app Answer: A Explanation: A droplet is the result of staging – a ready‑to‑run artifact containing the app code and dependencies. Question 37. Which command will list all the routes currently mapped to an application? A) cf routes APP B) cf app APP --guid C) cf curl /v3/apps/:guid/routes D) cf map-route --list APP
Practice Exam
Answer: C Explanation: Using the CF API via cf curl to /v3/apps/:guid/routes returns the route objects; there is no direct CLI command to list routes. Question 38. When using Docker images as the runtime for an app, which flag is required with cf push? A) --docker-image B) --docker-username C) --docker-push D) --docker-registry Answer: A Explanation: cf push APP --docker-image IMAGE_NAME tells CF to use the specified Docker image as the app’s root filesystem. Question 39. A service instance created with cf create-service can be deleted using which command? A) cf delete-service-instance B) cf purge-service-instance C) cf delete-service D) cf unbind-service Answer: C Explanation: cf delete-service SERVICE_INSTANCE removes the service instance (optionally with -f to force). Question 40. Which command generates a service key for a service instance named “mydb”?
Practice Exam
Question 43. When a Diego cell runs out of disk space, which component will prevent new app instances from being scheduled on it? A) Gorouter B) BBS (Bulletin Board System) C) Loggregator D) Cloud Controller Answer: B Explanation: The BBS tracks cell capacity; if a cell reports insufficient resources, the scheduler avoids placing new instances there. Question 44. The cf enable-feature-flag command can be used to: A) Turn on experimental platform capabilities such as diego_docker B) Activate user‑provided services automatically C) Grant Org Manager permissions to a user D) Enable log draining for an app Answer: A Explanation: Feature flags control optional or experimental features in the Cloud Controller. Question 45. Which manifest attribute determines the number of app instances to start after a push? A) instances B) count C) scale D) replicas Answer: A Explanation: The instances field in manifest.yml sets the desired instance count.
Practice Exam
Question 46. In a multi‑org environment, who can view the list of all organizations? A) Org Auditor B) Space Developer C) Cloud Controller admin (CC admin) D) Space Manager Answer: C Explanation: Only users with admin privileges on the Cloud Controller can list all orgs; regular org roles are scoped to their own org. Question 47. Which command shows the UUID (GUID) of an application? A) cf app APP --guid B) cf guid APP C) cf app APP --id D) cf get-guid APP Answer: A Explanation: cf app APP --guid prints the app’s globally unique identifier. Question 48. The cf ssh-code command is used to: A) Generate a one‑time password for SSH access to an app B) Retrieve the public SSH key of the current user C) List all active SSH sessions D) Disable SSH for an application Answer: A
Practice Exam
C) The Gorouter’s egress filter D) The app’s manifest egress section Answer: A Explanation: ASGs define egress rules; permitting only port 443 restricts the app to HTTPS outbound traffic. Question 52. Which command can be used to delete a route that is no longer needed? A) cf delete-route DOMAIN --hostname HOST B) cf unmap-route APP DOMAIN --hostname HOST C) cf remove-route DOMAIN --hostname HOST D) cf route-delete DOMAIN --hostname HOST Answer: A Explanation: cf delete-route removes the route from the router; cf unmap-route only detaches it from an app. Question 53. The cf curl command is primarily used for: A) Interacting directly with the Cloud Controller API B) Uploading large files to a service instance C) Performing health checks on apps D) Streaming logs over HTTP Answer: A Explanation: cf curl sends arbitrary HTTP requests to the CF API endpoints, useful for low‑level operations. Question 54. When an app instance crashes repeatedly, the platform’s default behavior is to:
Practice Exam
A) Permanently stop the app after three crashes B) Restart the instance with exponential back‑off until the desired count is met C) Delete the app and notify the Org Manager D) Scale the app down to zero instances automatically Answer: B Explanation: Diego’s BBS continuously attempts to keep the desired instance count, restarting crashed instances with back‑off. Question 55. Which of the following is NOT a built‑in buildpack provided by Cloud Foundry? A) Java Buildpack B) .NET Core Buildpack C) Go Buildpack D) Node.js Buildpack Answer: B Explanation: As of the core distribution, Cloud Foundry does not ship a .NET Core buildpack (it can be added manually). Question 56. To push an app without using a manifest file, which flag must you specify at minimum? A) --no-manifest B) --path C) --hostname D) --no-start Answer: B
