What Are Functions as a Service?

1. Introduction

Functions as a Service (FaaS) is a cloud computing model that allows us to focus on writing code without the hassle of managing servers or infrastructure.

In this tutorial, we’ll explore the working principles of FaaS, their advantages and disadvantages, and their practical applications.

2. Overview

Functions as a Service is a cloud computing model that revolutionizes how developers execute and manage code. With FaaS, our focus shifts from managing servers to writing and deploying individual functions. These functions, triggered by specific events, execute in a serverless environment, abstracting away the underlying infrastructure complexities.

3. Working Principles of FaaS

The working principles of FaaS involve several key components and processes that enable the execution of functions in a serverless environment.

In a typical FaaS setup, developers write functions that perform specific tasks or respond to particular events. These functions are then deployed to a FaaS platform, which manages the execution and scalability.

Let’s explore the key processes of the FaaS model:

• Function Development: Developers write individual functions that perform specific tasks or respond to specific events. These functions are designed to be stateless and modular, focusing on a single functionality or computation
• Function Deployment: The developed functions are packaged and deployed to a FaaS platform. The deployment process involves specifying the function’s code, dependencies, and any necessary configuration
• Event Triggering: FaaS functions are event-driven, meaning specific events or requests trigger them. These events can originate from various sources, such as HTTP requests, database updates, message queues, or scheduled timers
• Resource Provisioning: When an event triggers a function, the FaaS platform dynamically provisions the required resources to execute the function. This includes allocating CPU, memory, and other necessary resources for the function’s execution
• Function Execution: The FaaS platform executes the function within its isolated execution environment. The function performs the designated tasks or computations, utilizing the provided resources
• Scaling and Concurrency: FaaS platforms automatically scale the execution environment to handle fluctuations in demand. They can concurrently execute multiple instances of the same function to handle concurrent events or requests effectively

Following this process, FaaS enables developers to focus on writing modular functions while abstracting away the infrastructure management aspects. The platform handles resource provisioning, scaling, and concurrency, allowing applications to seamlessly respond to events and execute functions in a serverless environment.

3.1. Architecture of FaaS Model

The figure below shows a simple architecture of a FaaS model:

As we can see, the developer deploys functions through the application gateway to the cloud computing model. The FaaS provider provides the platform for running these functions. The FaaS provider triggers events in response to a user request and allocates resources to execute these functions.

3.2. Example

Now that we know the key processes involved in the FaaS model, let’s look into an example to understand these processes.

Suppose we’re building a social media platform and want to implement a function that sends email notifications to users when they receive a new message.

We’ll first develop a function specifically for handling the email notification task. We’ll then deploy the email notification to the FaaS platform, which provides the necessary infrastructure for executing the process when triggered.

An event is generated when a user receives a new message on the social media platform. This event triggers the execution of the email notification function. When a new message receives, the FaaS platform allocates the necessary resources for executing the email notification function, such as CPU and memory.

The email notification function retrieves the relevant information about the new message, composes an email, and sends it to the intended user(s). If multiple users simultaneously receive new messages, the FaaS platform automatically scales the execution environment by creating additional instances of the email notification function to handle the concurrent notifications efficiently.

4. Advantages and Disadvantages

Let’s take a look at the advantages and disadvantages of using FaaS.

4.1. Advantages

• Developer Productivity: FaaS abstracts away the complexities of infrastructure management, allowing developers to focus on writing concise and modular functions. This enables faster development cycles and easier maintenance of applications
• Scalability: FaaS allows our applications to scale effortlessly based on demand. FaaS providers automatically scale the required infrastructure to match the workload, ensuring efficient resource utilization
• Cost-effectiveness: FaaS follows a “pay-as-you-go” model, where we only pay for the actual execution time of our functions. Since we’re not responsible for managing and maintaining servers continuously, FaaS significantly reduces operational costs

4.2. Disadvantages

• Limited Execution Time: FaaS platforms typically impose limits on the maximum execution time of a function. This can be challenging if our application requires long-running tasks or computationally intensive operations
• Cold Start Latency: When a function is invoked after a period of inactivity, the FaaS platform must provide the necessary resources to execute the function. This process can introduce a noticeable delay, impacting the application’s responsiveness
• Limited Control over Infrastructure: FaaS abstracts away the underlying infrastructure, limiting our control over the execution environment and making it challenging to fine-tune or optimize certain aspects of our application

We’ll need to weigh these disadvantages against the benefits and suitability of FaaS for our specific application requirements.

5. Practical Applications of FaaS

Now that we know about FaaS, its key features and its advantages, let’s go through a few practical applications.

FaaS enables developers to build scalable and modular backend systems for web applications.

Suppose we’re developing a social media platform where users can upload images. We can use FaaS to separate the image processing function from the rest of the application. This will allow us to independently scale the image processing function based on demand, ensuring quick and efficient processing of user uploads.

We can also leverage FaaS for data processing tasks, such as ETL (Extract, Transform, Load) operations or real-time analytics. We can use different functions to process incoming data streams, perform computations, and store results in databases or trigger subsequent actions.

A simple example of data processing and analytics could be a scenario with a constant sensor data stream from the Internet of Things devices. By implementing FaaS functions to process and analyze this data in real-time, we can derive meaningful insights, trigger alerts, or store aggregated data for further analysis.

6. Conclusion

In this tutorial, we explored the concept of FaaS, its working principles, advantages and disadvantages, and its practical applications.

FaaS provides a serverless environment for executing functions, simplifying code execution and management. By leveraging FaaS, we can focus on writing modular functions that respond to specific requests while the underlying platform takes care of resource provisioning, scaling, and concurrency.