Serverless scripting is aptly named: it’s scripting, or computing, that occurs without a server. With serverless scripting, you upload JavaScript scripts to the cloud, which the cloud automatically deploys to the nearest data center.
When a piece of code is sent to a web server to control a website or app, it’s called server-side scripting. If it runs on the web browser, it’s called client-side scripting. In other words, the script runs on the side where it’s located.
Serverless scripting, in contrast, lets you write code without setting up or maintaining a server. The server is abstracted away from the developer and is handled by cloud-backed computing platforms like StackPath and products like Serverless Scripting.
Serverless scripts are run without a dedicated server and are executed in data centers close to the end user. Serverless scripting is often used for small tasks that need to be performed automatically, such as checking for new email messages or generating reports.
For example, say you have an image gallery written in PHP that uses Amazon S3 as its storage back-end. Through serverless scripting, whenever someone wants to view one of your photos, they will send a request directly to Amazon S3 that executes the appropriate PHP code to return the photo dynamically without ever involving a web server.
Serverless scripting uses two related technologies to multiply its benefits: serverless computing and edge computing.
Serverless scripting leverages serverless computing’s cloud-based execution model, in which the cloud provider runs the server and dynamically allocates machine resources on demand. Hence, developers only pay for what they use. This means you spend more time writing application code and less on backend development.
Serverless scripting is based on the functions as a service (FaaS) model, a cloud computing model that enables you to develop, run, and manage an application’s functionalities without building or maintaining the infrastructure.
Additionally, serverless computing and serverless scripting work together in how serverless functions are performed. These functions are developer-defined requests triggered by a user action or event. Then, these requests are made to the cloud. If the requests aren’t already running on the cloud, the service provider starts a new one, making the results available. Once the code is pushed, cloud service providers fully manage the process and scale servers as needed.
In addition to using serverless computing, serverless scripting also uses edge computing. In this distributed computing model, data processing and content delivery are placed closer to the network’s edge—in other words, closer to the user.
When serverless scripting requests are sent to the cloud service provider, they’re only sent to a nearby edge server or to a gateway used to communicate with edge devices to coordinate and monitor data. The edge network’s built-in computing capabilities handle the request on that nearby gateway or edge server, meaning the request doesn’t have to travel to the cloud for processing.
Serverless scripting is a programming technique that automates tasks that would otherwise be performed manually. When you use serverless scripting, you write code that the cloud provider executes on demand. Once executed, the cloud provider returns the results.
Once you push code onto a serverless scripting platform, it lets you upload scripts automatically deployed to the data center closest to the end user. This way, when a user’s request comes in, the code related to that request is executed in an individual sandbox environment.
By positioning the code at the edge and near the end user, you can quickly return responses, which allows you to automate tasks and work more efficiently. You can even modify requests before they go back to the origin server.
There are several advantages to using serverless scripting, including those highlighted below.
With a serverless infrastructure, you don’t have to upload code to servers or do any backend configuration to release a working version of an app. Unlike server-driven architectures, where you need to worry about server deployment, container provisioning, and scaling plans, you can upload code very quickly and release a new product with serverless scripting.
You can also upload the entire code base or one function at a time—after all, it’s just a collection of functions the cloud service provider provides. Similarly, updates, patches, fixes, or new app features are also deployed more quickly.
An application that isn’t hosted on an origin server can be run from anywhere—including at the edge. Because the client data is processed at an edge of the network closest to the user, deploying serverless scripts at the edge reduces latency since the data doesn’t need to travel as far. Using edge deployment also makes data more resilient and the transmission more secure due to the shorter trip with fewer chances for failure or attacks.
Furthermore, pushing serverless functions to the edge of networks minimizes the impact of “cold starts,” which refer to requests for code that hasn’t been used in a while and may load slowly.
It’s easy to see how less time managing servers leaves more time for actual coding. But a more striking shift in development pipeline management occurs with serverless: less time investment into monitoring DevOps practices and pipelines. This, in turn, reduces expenses and can lift server capacity constraints that limit developers from coding and expanding their applications. Without the serverless capability, this isn’t a possibility.
Serverless scripting automatically intercepts user requests. This allows you to modify the requests or response bodies to conform to proper, more secure standards without sending them to your origin. There’s no chance of doing this in client-side or server-side scripting, which doesn’t leverage edge deployment.
Though serverless scripting provides many benefits, there are some limitations that you need to take note of.
Although additional programming language support is in the works, serverless scripting currently only works with JavaScript. While JavaScript is a universal language used for a wide range of tasks, it is not well suited for certain types of applications. For example, JavaScript’s dynamic nature can make it difficult to optimize code for performance and doesn’t have strong support for multithreading. If an application doesn’t use JavaScript, it won’t be compatible with serverless scripting.
Because serverless scripting is request-only, it has inherent technical limitations that affect application performance.
For example, long-running tasks like video processing or data analysis become challenging because serverless scripting is invoked in response to events (like an HTTP request, for example). You can technically complete this task, but you’ll be paying for computing time just to keep a socket open for continuous requests, defeating the purpose of the on-demand advantage.
Similarly, serverless scripting is not well suited to an e-commerce site, which requires you to keep track of information such as items in a shopping cart. These workloads are better suited for traditional server architectures because the application needs to keep track of data from both the client and server sides.
You can’t use serverless scripting to up and replace your content delivery network (CDN), as they’re separate services.
CDNs are used to distribute content, including web pages and other files, across a network of servers so that users can access the content more quickly and reliably.
Serverless scripting is not well suited for replacing CDNs because it relies on short-lived processes that are run in response to events. This means serverless scripting isn’t meant for handling large amounts of traffic or distributing content across a wide area — which is the most significant benefit that CDNs provide.
