Fundamentals of Functions as a Service (FaaS) Quiz Quiz

Explore essential concepts of serverless computing with this Functions as a Service (FaaS) fundamentals quiz, designed to reinforce your understanding of event-driven execution, scalability, deployment, and related core principles. Assess your grasp of FaaS basics, benefits, limitations, and terminology with easy, scenario-based questions.

1. Definition of FaaS

   Which statement best describes Functions as a Service (FaaS) in the context of cloud computing?

   1. FaaS means purchasing hardware infrastructure for code deployment.
   2. FaaS allows code to run in response to events without managing servers.
   3. FaaS disables event-driven execution and enforces fixed schedules.
   4. FaaS is a traditional web hosting model requiring dedicated servers.

   Explanation: FaaS is a model where developers deploy individual functions that execute in response to specific events, without having to manage server infrastructure. The other options are incorrect because FaaS does not require purchasing hardware or dedicated servers, nor does it eliminate event-driven execution; in fact, it relies on it. Fixed schedules are not required in FaaS, as functions are triggered by events.

2. Event-Driven Model

   In FaaS, what typically triggers the execution of a function?

   1. The completion of a server backup
   2. An external event such as a file upload or API call
   3. The manual start of a virtual machine
   4. A scheduled hardware reboot

   Explanation: FaaS functions are usually triggered by external events like file uploads, API requests, or message arrivals, making the execution process dynamic and reactive. Scheduled hardware reboots and server backups are not typical triggers. Manually starting a virtual machine is unrelated to the event-driven nature of FaaS.

3. Scalability in FaaS

   How does FaaS handle demand when there is a sudden increase in incoming events?

   1. It queues excess events until servers can process them next week.
   2. It requires users to manually add more servers for scaling.
   3. It runs a fixed number of function instances regardless of demand.
   4. It automatically scales by launching additional function instances as needed.

   Explanation: FaaS provides automatic scaling by launching more function instances when demand increases, ensuring responsiveness. Running a fixed number of instances or queuing events for extended periods reduces efficiency and is not an FaaS feature. Manual server management contradicts the core principle of FaaS automation.

4. Typical Use Cases

   Which of the following is a common use case for FaaS?

   1. Hosting a large, persistent database
   2. Real-time processing of uploaded images for resizing
   3. Long-running scientific simulations that require persistent memory
   4. Running applications with continuous, 24/7 processes

   Explanation: FaaS is well suited for short-lived tasks like processing images upon upload, where functions are triggered by specific events. Long-running simulations and 24/7 processes are not ideal due to typical execution time limits. Hosting databases involves persistent storage needs, which FaaS is not designed for.

5. Deployment Method

   When deploying code using FaaS, how is the code typically delivered?

   1. By packaging small units of code as functions and uploading them
   2. By purchasing and shipping physical storage devices
   3. By hiring an administrator to manually edit server files
   4. By configuring and uploading virtual machine disk images

   Explanation: With FaaS, developers submit small, self-contained pieces of code, known as functions, directly to the platform. Unlike physical hardware or full virtual machine images, FaaS deployment focuses on specific code units. Manual server file editing is not required, making deployment more efficient and streamlined.

6. Resource Management

   Which responsibility is eliminated for users by adopting FaaS?

   1. Managing server operating systems and infrastructure updates
   2. Handling feature requests from users
   3. Writing application logic for business processes
   4. Creating test data for development

   Explanation: FaaS abstracts away server and infrastructure management, allowing users to focus on application logic. Writing business logic, handling feature requests, and creating test data remain the user's responsibility, as these tasks pertain to the application's purpose rather than basic infrastructure.

7. Pricing Model

   How are users typically billed for FaaS usage?

   1. By the number of administrators employed
   2. Based on the number of functions deployed, regardless of usage
   3. According to the time functions spend executing and resource consumption
   4. A flat monthly fee independent of activity

   Explanation: FaaS platforms generally charge users based on the number of function executions and the resources consumed during runtime. Simply deploying functions without usage, charging a flat monthly fee, or billing by administrator staff do not align with standard FaaS pricing models.

8. Cold Start Concept

   What is a 'cold start' in the context of FaaS?

   1. An instantaneous execution of a preloaded function
   2. A programming error that causes a function to overheat
   3. A scheduled shutdown of a function due to low temperatures
   4. A situation where function code is loaded and initialized before handling a first request

   Explanation: A cold start refers to the initial setup delay when a function is triggered after being inactive, as code needs to be loaded and prepared. Instantaneous execution applies to already warmed functions. No overheating is involved, and shutdowns due to temperature do not apply to serverless code.

9. Function Lifespan

   Which characteristic best describes the execution time of FaaS functions?

   1. They cannot be triggered by external events.
   2. They typically run for short periods and then terminate automatically.
   3. They are scheduled to start and stop once per day.
   4. They run indefinitely and must be manually stopped.

   Explanation: FaaS functions are meant to be ephemeral—starting in response to an event and terminating quickly after completing the task. Running indefinitely is not recommended or supported, and scheduled once-per-day starting contradicts event-driven operation. FaaS is specifically designed for event-triggered runs.

10. Statelessness in FaaS

    What does it mean for FaaS functions to be stateless?

    1. They automatically write their internal state to permanent disk after every execution.
    2. They require a local database to function correctly.
    3. They forget all state between invocations and do not store data from previous runs.
    4. They keep user session information permanently in memory.

    Explanation: Stateless FaaS functions do not retain information from one execution to another; each run is independent. Automatic state storage, reliance on local databases, and permanent memory retention are not core characteristics and undermine the stateless principle.