Scalability of ROR application

Business is peaking, traffic is increasing, and you are all set to maximise your revenue. But is your application ready to handle the increased user traffic? What if your application isn’t ready to handle the new workload?

Are you having scalability issues with your application as your business expands and traffic grows? Slow performance, longer wait times, and dissatisfied users can all result from your application’s inability to satisfy the changing expectations of its users. This typically causes users to abandon the application, which means lost revenue and reduced engagement for your business. To prevent these issues, application owners must understand how to develop a scalable and user-friendly application.

At Mallow, we have extensive experience building applications of various sizes across different domains. We understand the significance of scalability for application owners and the challenges they face in meeting the needs of their users.

This article aims to offer valuable insights into the crucial steps that guarantee the scalability of your Ruby on Rails application. By grasping the significance of scalability and adhering to our expert guidance, you can create and maintain a high-performance application that effectively engages users and ensures the prosperity of your business.

Why does scalability matter for my Ruby on Rails application?

The scalability of a Ruby on Rails application refers to its ability to handle increased workloads, user traffic, and growing data volumes without sacrificing performance or functionality.

Without proper scalability measures, an application can become slow, unresponsive, and even crash under a heavy load, resulting in a bad user experience, loss of revenue, and damage to the brand’s reputation.

A scalable Ruby on Rails application can seamlessly accommodate higher demand and adapt to changing circumstances without experiencing significant performance degradation or system failures. This includes efficiently scaling resources, such as servers and databases, to meet growing requirements, as well as implementing optimisation techniques to ensure smooth operation and responsiveness as the application and its user base expand. Therefore, having a scalable Ruby on Rails application is crucial for the success and sustainability of the application.

What factors determine the scalability of my Ruby on Rails application?

1. Architecture and Infrastructure

The scalability of an application is influenced by its architecture, with a well-designed one allowing for accommodating higher loads and traffic, whereas a poorly designed architecture may hinder scalability.

Moreover, the choice of hardware and infrastructure to host the application can impact its scalability. It is crucial for applications to effectively utilise server resources, such as CPU and memory, to ensure they can handle increased traffic. Moreover, adhering to coding best practices aids in efficiently using hardware resources.

2. Efficient SQL queries

The application should efficiently use database queries to reduce the load on the database server. This can involve optimising queries to use indexes, reducing the number of queries required to generate a page, and minimising the data retrieved from the database.

3. Caching

This plays a vital role in ensuring the scalability of a Ruby on Rails application. By storing frequently accessed data or the data produced from expensive operations in memory, caching reduces the load on the underlying resources such as the database or external services. This helps to reduce resource utilisation and minimises the response time for subsequent requests. This allows the application to handle a higher volume of traffic without experiencing performance degradation.

Caching can be implemented at various levels, such as page caching, action caching, fragment caching, or database query caching. Each level targets specific areas where caching can have the most significant impact.

4. Proper configurations of web and application servers

The appropriate use of concurrency like multi-threading, number of processes, maximum request size, and other web servers and application server tuning parameters will influence the application’s scalability.


How can I check the scalability of my Ruby on Rails application?

Checking if a Ruby on Rails application is scalable involves a series of tests and evaluations to determine how the application behaves under different load and traffic conditions.

1. Load Testing

Load testing involves simulating many users or requests to the application to determine its behaviour under heavy load. Load testing can help to identify performance bottlenecks, server or node capacity issues, and other scalability problems. Load testing for your application can be conducted using various tools available in the market.

An example of a popular load-testing tool is Apache JMeter. It allows you to create realistic test scenarios by simulating multiple concurrent users. It lets you measure your application’s performance, identify performance bottlenecks, and analyse its behaviour under different load conditions.

Attached below is a sample of what the results from JMeter look like.

Load Testing

2. Stress Testing

JMeter is again a tool that can come in handy for you in handling stress testing for your application. Stress testing entails subjecting the application to extreme loads or traffic to assess its ability to handle such conditions. By conducting stress testing, potential vulnerabilities in the application’s architecture or infrastructure that could impact its scalability can be identified.

3. Capacity Planning

Capacity planning entails predicting the future requirements of the application and determining the necessary resources to accommodate higher loads or increased traffic. By engaging in capacity planning, one can identify any limitations in capacity or resources that could impact the application’s scalability.

4. Performance Monitoring

If you are monitoring your application and notice some of the requests are slow, this is the first indication that your application might not be scalable. Monitoring the application’s performance metrics, such as the slowest response time, server load, database performance, and other metrics, can help identify any issues affecting the application’s scalability.

Performance Monitoring

Using these testing and evaluation methods, Ruby on Rails developers can identify any scalability issues in their application and take the necessary measures to improve its scalability and performance.

Optimise your Ruby on Rails Application Get a free consultation to improve your Ruby on Rails application 

What should I do if my application is not scalable?

If your Ruby on Rails application is not scalable, there are several steps you can take to improve its scalability and performance. Here are some suggestions on the solutions you can consider going with.

1. Use load balancing and scaling

Load balancing is necessary for horizontal scaling because it distributes incoming network traffic across multiple servers, ensuring efficient utilisation of resources and preventing any single server from becoming overwhelmed.By evenly distributing the workload, load balancing allows the application to scale horizontally, where additional servers can be added to handle increased traffic. This enhances performance and reliability, allowing for better resource allocation and improved scalability as the application grows.Vertical scaling involves increasing the capacity of a single server or node by adding more resources such as CPU, memory, or disk space. While there are limitations to vertical scaling, it can be a valuable technique for applications that require additional processing power or memory. Using vertical scaling is generally recommended for databases instead of horizontal scaling.

2. Use caching

Both static caching and dynamic caching enhance application scalability by reducing server load and improving response times.


Static caching stores static content, like images and HTML pages, in a cache, enabling direct serving to users without accessing application servers. This reduces server workload and eliminates repetitive content generation. Content Delivery Networks (CDNs) can further augment these caching techniques by distributing cached content across geographically dispersed servers, reducing latency and improving scalability on a global scale.On the other hand, dynamic caching caches dynamically generated content, such as database query results and API responses, for quick serving to subsequent users. Dynamic caching frequently accessed data minimises the need for complex computations and database queries, enhancing performance and scalability.

3. Optimise the database

Optimising the database can increase the scalability of your Ruby on Rails application by improving its performance and efficiency. Techniques such as indexing, query optimisation, and denormalisation can enhance database operations, reducing response times and allowing the application to handle higher volumes of data and user traffic.

Indexing plays a crucial role by creating indexes on frequently queried columns, allowing faster data retrieval. Additionally, query optimisation techniques, such as avoiding unnecessary joins and optimising complex queries, can significantly improve database performance. Denormalisation, the process of strategically duplicating data, can be utilised to minimise expensive joins and reduce database load.

Furthermore, implementing caching mechanisms, both at the application and database level can further enhance scalability by reducing the need for frequent database accesses. By employing these strategies, your Ruby on Rails application can efficiently handle more extensive datasets and increased user traffic, ensuring optimal scalability.

4. Asynchronous Processing

Employing asynchronous processing for time-consuming or resource-intensive tasks. The main application can handle requests more efficiently by offloading these tasks to background workers or job queues, improving scalability.

pull request

5. Cloud Services

Leverage cloud platforms like Amazon Web Services (AWS), Google Cloud Platform (GCP), or Microsoft Azure to benefit from their scalable infrastructure. Services like auto-scaling, load balancers, and managed databases can automatically handle traffic fluctuations and scale resources.

6. Addressing Memory Leaks

Optimising the application’s codebase can help reduce resource (CPU and memory consumption) utilisation by addressing memory leaks. This ultimately helps in improving application performance and scalability.

7. Microservices Architecture

Adopt microservices architecture, dividing the application into smaller, loosely coupled services. Each service can be independently scalable, allowing specific components to be scaled based on demand while keeping the overall system responsive.

8. Performance optimisation

When an application is designed and optimised for performance, it tends to have better scalability. Improving performance often involves optimising code, and database queries, and utilising caching mechanisms, among other techniques. These optimisations can enhance the application’s ability to process requests quickly and efficiently.By improving performance, the application can handle larger numbers of concurrent users, higher volumes of traffic, and larger datasets without experiencing performance degradation. This increased capacity to handle a growing workload is a key aspect of scalability. Conversely, a lack of performance optimisations can hinder scalability.

How can I ensure having the right architecture for my Ruby on Rails application?

If your Ruby on Rails application lacks scalability, there are steps you can take to address this issue and improve its performance. Start by identifying specific bottlenecks in your application using profiling and monitoring tools.

Optimise critical sections of your code by employing techniques such as caching, database optimisation, and query optimisation. Implement background processing for time-consuming tasks to enhance concurrency.

Consider introducing horizontal scalability by deploying your application across multiple servers or utilising cloud-based services. Regularly test your application under realistic workloads to gauge performance and make necessary adjustments. By following these best practices, you can ensure that your Ruby on Rails application can handle increased traffic and growing user demands effectively. Ultimately, having a scalable application can enhance the performance of your application, leading to improved user experience and better business outcomes.

Having the right architecture for your Ruby on Rails application is paramount when considering scalability. With a well-designed architecture in place, your application becomes more resilient to handle increased traffic and user load without sacrificing performance. Modular and decoupled components enable easier scaling of specific parts of the application, allowing for the addition of more servers or microservices as demand grows. Check out our article on How can I validate the architecture of my Ruby on Rails project?

Feel as if we could help you solve your issues on the application’s scalability or any other problems? Please feel free to reach out to our team.



Jayaprakash is an accomplished technical manager at Mallow, with a passion for software development and a penchant for delivering exceptional results. With several years of experience in the industry, Jayaprakash has honed his skills in leading cross-functional teams, driving technical innovation, and delivering high-quality solutions to clients. As a technical manager, Jayaprakash is known for his exceptional leadership qualities and his ability to inspire and motivate his team members. He excels at fostering a collaborative and innovative work environment, empowering individuals to reach their full potential and achieve collective goals. During his leisure time, he finds joy in cherishing moments with his kids and indulging in Netflix entertainment.

Leave a comment

Your email address will not be published. Required fields are marked *