Azure Functions
By Microsoft
Azure Functions is Microsoft Azure's serverless compute service for running event-triggered code without provisioning or managing servers, billed based on execution time and resource consumption.
Definition
Azure Functions is Microsoft Azure's serverless compute service for running event-triggered code without provisioning or managing servers, billed based on execution time and resource consumption.
Overview
Azure Functions plays the same role in the Azure ecosystem that AWS Lambda plays in AWS: developers write functions that respond to triggers — HTTP requests, timers, messages on Azure Service Bus or Storage Queues, changes in Cosmos DB, and more — and Azure handles provisioning and scaling the compute needed to run them. Functions are organized around a triggers-and-bindings model, where triggers determine what starts a function execution and bindings provide a declarative way to read from or write to other Azure services without writing boilerplate connection code. Azure Functions supports multiple hosting plans with different trade-offs: a Consumption plan that scales to zero and bills per execution, a Premium plan that keeps instances warm to avoid cold starts while still auto-scaling, and a Dedicated (App Service) plan that runs functions on already-provisioned Azure App Service infrastructure for predictable, always-on workloads. It supports several language runtimes including C#, JavaScript/TypeScript, Python, Java, and PowerShell. Because Functions is deeply integrated with the rest of Azure's service catalog, it's commonly used as the glue layer in event-driven architectures — reacting to blob storage uploads, processing messages, or exposing lightweight HTTP APIs — much as Lambda is used within AWS-centric architectures.
Key Features
- Event-driven execution via a triggers-and-bindings programming model
- Multiple hosting plans: Consumption, Premium, and Dedicated
- Scales to zero on the Consumption plan to minimize idle cost
- Premium plan option to reduce cold-start latency
- Support for C#, JavaScript/TypeScript, Python, Java, and PowerShell
- Declarative bindings to read/write other Azure services without boilerplate
- Built-in integration with Azure Monitor for observability
- Durable Functions extension for stateful, long-running workflows
Use Cases
Frequently Asked Questions
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