Functions

Azure Functions hosts code routines (Functions) that run in reaction to events or on a regular schedule. Functions are hosted on one or more VMs, which can be automatically provisioned in a serverless fashion and scaled to handle incoming event traffic demands.

Service Overview and Benefits

Functions can run without requiring a VM to be continually active and incurring charges (thus, the term “serverless” is used to describe the model). The service could reduce costs compared to deployments that require the continuous use of compute resources even as they are idle awaiting an event or a scheduled run time.

Durable Functions allow the state created by the execution of a Function to be preserved. Durable Functions enable certain complex Function calling scenarios, such as Functions that call other Functions, long-running Functions, and Functions that depend on human interactions.

Several programming languages and trigger types are supported, so the service could be applicable to many solutions. Furthermore, custom handlers allow customers to extend Functions to support additional programming languages. Function code can reference external data such as an Azure Cosmos DB database.