Function as a service (FaaS) is a category of cloud computing services that provides a

platform Platform may refer to: Technology * Computing platform, a framework on which applications may be run * Platform game, a genre of video games * Car platform, a set of components shared by several vehicle models * Weapons platform, a system or ...

allowing customers to develop, run, and manage application functionalities without the complexity of building and maintaining the infrastructure typically associated with developing and launching an app. Building an application following this model is one way of achieving a "

serverless Serverless computing is a cloud computing execution model in which the cloud provider allocates machine resources on demand, taking care of the servers on behalf of their customers. "Serverless" is a misnomer in the sense that servers are still ...

" architecture, and is typically used when building

microservices A microservice architecture – a variant of the service-oriented architecture structural style – is an architectural pattern that arranges an application as a collection of loosely-coupled, fine-grained services, communicating through lightw ...

applications. FaaS was initially offered by various start-ups circa 2010, such as PiCloud.

AWS Lambda Amazon Web Services, Inc. (AWS) is a subsidiary of Amazon that provides on-demand cloud computing platforms and APIs to individuals, companies, and governments, on a metered pay-as-you-go basis. These cloud computing web services provide di ...

was the first FaaS offering by a large public cloud vendor, followed b
Google Cloud Functions

Microsoft Azure Microsoft Azure, often referred to as Azure ( , ), is a cloud computing platform operated by Microsoft for application management via around the world-distributed data centers. Microsoft Azure has multiple capabilities such as software as a ...

Functions, IBM/

Apache The Apache () are a group of culturally related Native American tribes in the Southwestern United States, which include the Chiricahua, Jicarilla, Lipan, Mescalero, Mimbreño, Ndendahe (Bedonkohe or Mogollon and Nednhi or Carrizaleño an ...

OpenWhisk IBM Cloud, (formerly known as Bluemix) is a set of cloud computing services for business offered by the information technology company IBM. Services As of 2021, IBM Cloud contains more than 170 services including compute, storage, networki ...

(

open source Open source is source code that is made freely available for possible modification and redistribution. Products include permission to use the source code, design documents, or content of the product. The open-source model is a decentralized sof ...

) in 2016 and

Oracle Cloud Oracle Cloud is a cloud computing service offered by Oracle Corporation providing servers, storage, network, applications and services through a global network of Oracle Corporation managed data centers. The company allows the ...

Fn (open source) in 2017.

Use cases

Use cases for FaaS are associated with "on-demand" functionality that enables the supporting infrastructure to be powered down and not incur charges when not in use. Examples include data processing (e.g.,

batch processing Computerized batch processing is a method of running software programs called jobs in batches automatically. While users are required to submit the jobs, no other interaction by the user is required to process the batch. Batches may automatically ...

stream processing In computer science, stream processing (also known as event stream processing, data stream processing, or distributed stream processing) is a programming paradigm which views data streams, or sequences of events in time, as the central input and ou ...

, extract-transform-load (ETL)),

Internet of things The Internet of things (IoT) describes physical objects (or groups of such objects) with sensors, processing ability, software and other technologies that connect and exchange data with other devices and systems over the Internet or other comm ...

(IoT) services for

Internet The Internet (or internet) is the global system of interconnected computer networks that uses the Internet protocol suite (TCP/IP) to communicate between networks and devices. It is a '' network of networks'' that consists of private, pub ...

-connected devices,

mobile app A mobile application or app is a computer program or software application designed to run on a mobile device such as a phone, tablet, or watch. Mobile applications often stand in contrast to desktop applications which are designed to run on d ...

lications, and

web application A web application (or web app) is application software that is accessed using a web browser. Web applications are delivered on the World Wide Web to users with an active network connection. History In earlier computing models like client-serve ...

s. Another real-world use case can be creating

API An application programming interface (API) is a way for two or more computer programs to communicate with each other. It is a type of software interface, offering a service to other pieces of software. A document or standard that describes how ...

s for already built applications without breaking down or modifying the current or existing functionality of the application.

Comparison with PaaS application hosting services

Platform as a service Platform as a service (PaaS) or application platform as a service (aPaaS) or platform-based service is a category of cloud computing services that allows customers to provision, instantiate, run, and manage a modular bundle comprising a computin ...

(PaaS) application hosting services is similar to FaaS in that they also hide "servers" from developers. However, such hosting services typically always have at least one server process running that receives external requests. Scaling is achieved by booting up more server processes, which the developer is typically charged directly for. Consequently, scalability remains visible to the developer. By contrast, FaaS does not require any server process constantly being run. While an initial request may take longer to be handled than an application hosting platform (up to several seconds), caching may enable subsequent requests to be handled within milliseconds. As developers only pay for function execution time (and no process idle time), lower costs at higher scalability can be achieved (at the cost of latency).

References

{{Cloud computing Serverless computing As a service

Use cases

Comparison with PaaS application hosting services

See also

References