Explore foundational concepts of serverless deployment models, focusing on cloud functions and event-driven compute in the major public clouds. Assess your understanding of serverless computing triggers, scaling, billing, and supported use cases in a cloud-agnostic context.
Which type of event commonly triggers a serverless cloud function, such as when a new file is uploaded to storage?
Explanation: A file system change, like uploading a new file, often triggers a serverless function in the cloud. Scheduled timers are another valid trigger type but are not specifically related to file uploads. A failed disk or software crash typically triggers alerting or recovery mechanisms, not event-driven functions.
What is a key benefit of serverless deployment models when handling unpredictable workloads?
Explanation: Serverless functions automatically scale up or down in response to incoming events, providing efficient resource use. Manual scaling requires user intervention and is contrary to the serverless approach. Always-on virtual machines and fixed resource allocation do not offer the flexibility or cost savings typical of serverless.
How are users commonly billed for cloud functions in a serverless model?
Explanation: Serverless platforms generally charge based on runtime and the amount of resources consumed by function executions. Billing by deployed virtual machines or by storage only does not reflect actual function usage. Monthly flat fees are uncommon for serverless compute, where usage varies.
Why are serverless cloud functions typically considered stateless?
Explanation: Each serverless function invocation is isolated and does not retain data from previous runs, making them stateless by design. They do process data for each run but do not keep it afterward. Storing data locally or needing persistent connections does not fit the serverless execution style.
Which scenario is best suited for serverless functions in cloud environments?
Explanation: Handling tasks like resizing images immediately after upload fits serverless models well, using event-driven and short-lived execution. Continuous batch processing and long-running web servers are better with dedicated or containerized servers. Serverless is not intended for hosting databases, which require persistent storage and processes.
What does a 'cold start' refer to in serverless cloud functions?
Explanation: Cold start means the brief delay when a serverless function starts for the first time, as underlying resources are set up. It's not about running functions before upload or data moving to cold storage. An unexpected server power loss is unrelated to how serverless functions launch.
How should persistent state be managed when using serverless deployment models?
Explanation: Since serverless functions are stateless, persistent data must be stored externally, such as in managed databases or file storage. Variables inside a function or in RAM are temporary and lost after execution. Ignoring persistent needs leads to data loss.
Which statement best describes resource limits of serverless cloud functions?
Explanation: Serverless functions are subject to maximum runtime and memory limits to ensure fair usage and platform efficiency. Unlimited runtime or memory would disrupt shared infrastructure. Functions are designed for short tasks rather than indefinite running.
Which languages are typically supported by cloud serverless function services?
Explanation: Cloud providers support popular high-level languages such as Python, JavaScript, and Java for serverless functions. Assembly, COBOL, or proprietary code are rarely supported. Spreadsheet formulas are not used for programming cloud functions.
What is an essential step when deploying a serverless function to a cloud platform?
Explanation: Deploying a serverless function requires uploading your source code or packaged application to the cloud provider's service. There is no need to configure hardware or physical servers, and tasks like burning to optical media or editing firmware are unrelated to cloud deployments.