Azure Functions & Serverless Computing Flashcards

Which Azure Functions Premium Plan feature ensures at least one function instance is always warm to eliminate cold starts?

Answer: Pre-warmed instances

Pre-warmed instances on the Premium Plan keep at least one instance initialized so the first request does not incur a cold-start delay.

When using the Timer trigger in Azure Functions, which expression format is used to define the schedule?

Answer: CRON expression

Timer triggers use a CRON expression (with an optional sixth field for seconds) to define when the function should fire.

In Azure Functions, what is the purpose of the host.json file?

Answer: Configure global settings for the function app host

host.json contains global configuration options that affect all functions in the app, such as logging levels, retry policies, and extension settings.

Which Azure Functions trigger automatically scales based on the number of messages in a queue?

Answer: Queue Storage trigger

The Azure Queue Storage trigger monitors queue depth and scales out function instances automatically when messages accumulate.

What is the role of the Durable Functions 'Entity function'?

Answer: Store and manage stateful objects identified by an entity ID

Entity functions (Durable Entities) define operations that read and write small pieces of state, each identified by a unique entity ID.

Which setting in local.settings.json is required to run Azure Functions locally?

Answer: FUNCTIONS_WORKER_RUNTIME

FUNCTIONS_WORKER_RUNTIME specifies the language worker (e.g., dotnet, node, python) and is required for the local runtime to load the correct worker process.

Which Azure Functions output binding lets a function publish messages directly to an Azure Event Hub?

Answer: Event Hub output binding

The Event Hub output binding allows a function to send one or more events to an Event Hub without writing any Event Hubs SDK code.