Create a scalable web application
Scalability is one of the most critical conditions for the success of a web application. In this article, we will tell you what to keep in mind during the development to meet the principles of scalability. Also, you will learn:
- what can limit the structure of a sustainable and scalable web application;
- what technologies embody the idea of scaling to life;
- how to develop an app that will withstand the visitors’ inrush on the crest of a success wave and painlessly transfer the expansion of functionality at any development and operation stage.
Where to begin a scalable development? To better understand the underlying principles and highlight the advantages of this approach, we will cover various related concepts, types of application architecture, and popular frameworks.
What you will learn in this post:
- Why does one need scalability?
- What is scalability?
- Scalable app architecture
Why does one need scalability?
Looking at the websites of the frontline companies, we don’t always realise what kind of workload they are to withstand. Neither do we think about the importance of high productivity and usability for the success of the company.
Therefore, when the newcomers start building their first websites, they don’t know about some problems they may run into later:
- an increase in the number of visitors reduces the performance of web applications and blows up the failures;
- expansion of the product range negatively affects the page load time; updating the inventory of an e-commerce shop becomes problematic;
- changing the code structure becomes dangerous and overcomplicated; adding a new product or service take too much time and becomes expensive, and the possibility of carrying out the A/B tests reduces.
As a result, the business has wasted opportunities if the problem hasn’t been solved, and the restrictions persist.
Do all websites inevitably face such problems?
To one extent or another, most of them experience such issues. However, the degree of their complexity depends on how well the web applications were designed from the very beginning.
Scaled development is not a special kind of development. It’s a set of principles and techniques that help you design an application to a high standard.
By sticking to specific rules of the application setup, you will be able to:
- reduce the page load time, number of errors, time to implement changes, and the cost to update the site;
- improve the user experience;
- extend the life cycle of the services or products offered;
- as a result, increase sales and brand loyalty.
What is scalability?
The website scalability definition is the ability of a system, network, or process to cope with the increase in workload when adding resources (usually hardware).
Scalability can be assessed through the ratio of the increase in system performance to the rise in resources used. Also, scalability means the ability to add extra resources while keeping the structure of the central node intact.
In a system with poor scalability, adding resources leads only to a slight increase in performance, and after reaching a certain threshold, boosting the resources does not have any effect at all.
In addition to scalability, there is a number of related concepts that help better understand the problem. One of them is recoverability.
Recoverability is the ability of the system to restore its operability after a failure. It is closely related to the concept of a saturation point.
A saturation point is a certain degree of the workload intensity at which the system begins to malfunction. Unjustified jumps in the operation of the system usually lead to failure.
Under normal conditions, the program’s performance changes proportionally to the load, which increases gradually. If at some point the predictable growth is replaced by abnormal jumps – the saturation point has been reached.
Testing aimed at identifying this point is called a ramp up test. It helps to determine the reliability and scalability of a web application, as well as identify the system bottlenecks that undermine the effective operation of the entire system.
What characteristics affect the web application scalability?
- Architecture. This is one of the most important parts of app scalability.
- Framework load. Sometimes scalability is limited to the framework, so its choice affects the performance of an app with the increase of features.
- Sustainable design. The quality of code also significantly affects scalability.
- Sustainable load testing. With proper load and performance testing, you’ll be able to find and eliminate the bottlenecks of your app and ensure its smooth growth.
- Hardware limitations. As you see, notonly software can affect scalability.
- Third-party component integration. It is the most widespread cause of bottlenecks and failures in operation.
Scalable app architecture
We’ve just discovered that the app architecture makes a big difference in scalability. Now, let us go into details of how a scalable app should be designed.
Frontend vs Backend
A frontend is the visible part of a web application the user interacts directly with.
In the software configuration, many levels between the hardware and the end user may exist. Each of them can also have a frontend and a backend.
The frontend is an abstraction that provides a user interface. For example, open a new tab of the browser, type the address of some website, and press Enter. The website should load instantly. A well-designed page template is understandable, and the visual component is impressive, simple and easy to navigate.
However, in addition to being easy to use, a properly designed frontend also helps avoid problems with scalability in the future.
Backend stands for everything that happens on the server. It interprets everything the user does on the frontend, communicates it to the database if necessary and sends a response back to the browser.
This part takes up to 80% of the entire code and affects the performance of the whole application the most.
Backend is responsible for the dynamic processes on the page and data storage management, which makes it more prone to bottlenecks. The backend can be built with any multifunctional programming language like Javascript, Python, Ruby, C#, etc.
Usually NGINX is used (Used Apache in old times, Microsoft has IIS and Passenger for Python and Ruby) to route requests. The containers usually run in different ports but we usually expose only port 80 to the world (For security reasons), so that no one from outside can connect to our databases.
Vertical vs horizontal scaling
Vertical scaling implies a performance increase of each system component to improve overall performance.
Scalability, in this context, means the ability to replace the components of an existing computing system with more powerful and faster ones as requirements grow, and technology develops.
It is the easiest scaling approach since it doesn’t require any changes to the application programs running on such systems.
Horizontal scaling is when you separate the system into smaller structural components, space it across individual physical machines, and increase the number of servers that execute the same function simultaneously.
In this case, scalability is the ability to add new nodes, servers, and processors to the system to increase overall performance.
This scaling approach may require changes to the programs so that they fully utilise the increased amount of resources.
Django is one of framework to explore while designing scalable web applications. This high-level and extra fast Python web framework supports the clean and pragmatic design of the applications which contributes to the scalability as well.
Resources:
How to make a successful scalable web application?
