Developing an application the right way and ensuring it can be scaled up allows you to prepare your project for a growing number of users. But how do you scale a web application, and when should you consider it?
Scaling a web application is often considered one of the last stages of creating a web app. But this approach is usually wrong. What if your traffic increases in a relatively short time? If you don’t prepare for it early enough, the app’s performance will suffer and you will lose potential customers. Moreover, the faster you scale your application, the lower the cost and effort will be.
Table of Contents
What is web application scalability?
Web application scalability is the potential of an application to grow over time (i.e., how the app copes with the growing number of users). A scalable application is one that works well both when several or thousands of users generate low or high traffic. It is essential to ensure a positive user experience.
Scaling a web application requires an appropriate approach to system architecture and application development that takes into account the app’s elements. It is also about choosing the right cloud solutions and knowing how to configure them correctly to suit your needs. It’s a long process, not a simple tweak that can be implemented in a few minutes.
How to scale a web application
Many factors affect web application scalability, so it’s important to optimize the app’s elements. For better performance, it’s good to use available tools that help optimize the code and prepare the configuration to avoid unpleasant surprises. Below you’ll find the basic things you should implement when building a web application.
Cloud computing services help you scale elastically, as they make it easier to scale server parameters or create new server instances where the application is installed. You need to choose what’s best for your app — horizontal or vertical scaling.
- Vertical scaling means upgrading server hardware. Thanks to cloud computing, you can add more resources, easily expand RAM capacity, increase the number of virtual CPUs (vCPUs), or increase disk capacity.
- Horizontal scaling is about adding more machines to an existing stack to handle more requests from app users. The downside is that it adds complexity to your system. So, before you implement such an approach, take care of the following elements:
- Manage load by dividing the system dataset and load over multiple servers. This allows you to add more independent machines to a system that connects to a given database to spread the load and increase capacity as required. You can use a fully hosted and managed database engine such as AWS RDS or DigitalOcean Managed Databases.
- Using a load balancer to manage traffic between servers. It’s worth using ready-made solutions such as AWS or DigitalOcean to improve work and save time. For instance, AWS Auto Scaling monitors applications and automatically scales capacity up or down.
As I mentioned, to use horizontal scaling or autoscaling, you need to separate the database on a separate server. But it’s not enough, as it must be properly configured to ensure system operations run smoothly. Thus, it’s necessary to create appropriate indexes or optimize queries that will be executed quickly. Doing this will allow you to efficiently handle a growing number of queries per second.
A server that processes requests should go hand in hand with properly configured caching to reduce the load on your database engine. So, every time the application queries for data, it can be retrieved from the cache without querying the database. You can use solutions such as Redis or Memcached for this.
Writing clean code that makes an app easy to maintain is a must. With that in mind, avoid unnecessary loops and complicated and non-optimized algorithms. Use design patterns that help you create good quality software — it will be much easier to make changes to your app without trying to connect the dots and understanding previous work.
Using a content delivery network
A content delivery network (CDN) such as Cloudflare helps offload the application by shifting some traffic to the CDN. As it stores a cached version of your app content in multiple geographical locations, the CDN loads its content from servers closest to the users. As a result, you avoid unnecessary queries to your server, which speeds up the loading of the application.
Besides the things mentioned above, it’s also important to test and monitor your web application, as it will help you quickly identify possible problems and catch errors before your users do it.
Effective web application scalability depends on many factors, but when you use available tools the right way, you improve app performance and can react quickly when traffic suddenly spikes. Using the right approach, you’ll also enjoy more efficient use of resources during low-traffic periods.