Introduction
A web application may have no visible errors with a few hundred users, but the same application may behave completely differently with thousands of simultaneous users. Pages may stop loading, requests begin to time out, and important features may stop working in extreme cases. The entire application can go offline.
Most of these issues are caused by factors outside of traffic volume. They may be attributed to poor application, database, or server configuration, poor coding logic, or poor use of caching. Businesses developing Web Application Development should be thinking about these factors before they experience issues caused by high traffic volume.
What Happens When a Web Application Receives Heavy Traffic?
Each user request to open a page, fill out a form, search for something, or complete a transaction requires the application to process one or more requests. These requests use application resources such as CPU, memory, database connections, and network resources.
If the number of simultaneous requests exceeds the capacity of the available infrastructure, the application will begin to perform poorly. This may result in slow page load times, failed requests, or unpredictable application errors.
Some common symptoms include:
- Slow page loads
- Frequent server time-outs
- Database connection issues
- Spikes in CPU and memory usage
- Failed transactions
- Crashed applications
- Unresponsive application elements
Most of the problems mentioned above are usually not due to too much traffic. They are mainly due to a lack of capacity or bad architecture.
1. Insufficient Server Resources
Failure of the application to serve requests is due to insufficient server capacity. Inadequacy of any of the following resources: CPU, memory, storage, or bandwidth will negatively impact application performance if requests exceed the server’s ability to process them.
An application running on a small server may be able to handle normal day-to-day operations, but a new marketing campaign or product launch may very quickly take up all the available resources with thousands of simultaneous requests.
A Web Development Company can assess the usage of the available resources and decide whether the application needs better infrastructure, a more optimized server, or additional resources.
2. Poor Database Performance
The database is often one of the biggest bottlenecks in a high-traffic application. Every user request may require the application to retrieve, update, or insert information. If database queries are inefficient, response times increase as traffic grows.
A query that takes a couple of milliseconds to execute when traffic is light may be a critical issue when thousands of requests execute it. Poor database performance can be the result of lost indexes, unoptimized joins, large datasets, or large numbers of repeated queries.
Developers can improve database performance by:
- Adding indexes
- Optimizing slow queries
- Reducing unnecessary database requests
- Utilizing database caching
- Archiving old data
- Monitoring query performance
Database optimization should be treated as an ongoing process rather than a one-time task.
3. Lack of Caching
Without caching, an application will perform the same calculations or database requests, one after the other, for individual users. This also means a waste of server resources and an increase in time for responses.
Caching stores information that is requested frequently. With caching in use, there is no need to perform the same request repeatedly, and hence the requested information can be sent at a faster speed. The type of caching to be used depends on the application. Browser caching, server caching, database caching, and content delivery networks (CDNs) are some of the caching techniques.
For example, product information that rarely changes does not necessarily need to be retrieved from the database every time someone visits a page. A cached version can significantly reduce processing requirements.
Caching, used cleverly, will improve the performance of your application and reduce server load.
4. Inefficient Application Code
The best servers can't bring up an application where developers have written poor code. Code that, for instance, contains many database calls, several loops and processes that require a lot of memory, and not well-defined backend processes, can consume too much of server resources.
Issues of inefficient code may be invisible during testing, because in most cases the servers are less busy than in production environments. Thousands of simultaneous requests will display the inefficiency instantly.
Developers need to use profiling and performance monitoring tools to identify the most resource-intensive functions and then refactor the inefficient code.
5. No Load Balancing
If a server is the only one handling requests, it will eventually fail as it reaches its processing limits. Load balancing divides the incoming requests across all available servers. Instead of making one server handle everything, the request is spread across all of the servers.
The process of Load balancing is distributing the requests across multiple servers. The requests are shared among multiple servers to minimize the usage of a single resource.
This approach provides several benefits:
- Even load distribution
- Improved availability
- Optimized resource usage
- Easy horizontal scaling
- Great fault tolerance
One of the advantages of this type of balancing is that in cases where a server fails, the available healthy instances can be redirected to minimize the downtime.
6. Sudden Traffic Spikes
Businesses usually experience spikes in traffic due to many reasons, like advertisements, product launches, viral media, increased social activity, etc.
There are multiple ways to handle spikes, like auto scaling, load balancing, caching, and monitoring. Capacity planning in such scenarios should focus more on the peak traffic rather than the average use.
Before launching a major enterprise campaign, testing the application with simulated traffic can help identify and address weaknesses.
7. Poorly Designed Third-Party Integrations
Web applications depend on external services to process payments, fetch maps, authenticate users, make API calls, and provide other functionality. If any service takes a long time to respond, the web application may become slow as well.
For example, if a web page waits for several external API responses before it can render, a slow API response by one service may result in a bad user experience for all services.
Developers should implement timeouts, asynchronous processing, caching, and fallbacks where appropriate. External dependencies must never become unnecessary bottlenecks for the application.
8. Memory Leaks and Resource Management
A memory leak is when an application continues to use memory without freeing resources that are no longer needed. The issue can appear to be of no concern with light traffic; however, memory consumption can grow with a sudden surge in traffic.
Eventually, the server is going to run out of available memory to use, causing processes on the server to become slower and even crash.
Using performance monitoring and profiling tools can help identify abnormal memory usage. Application developers should investigate and review services that continuously consume memory.
How Can Businesses Prevent High-Traffic Failures?
Traffic-related failures can be prevented by a combination of application optimization, adequate planned infrastructure, and continual monitoring. There is rarely a one-size-fits-all solution to application optimization.
A strong strategy usually includes:
- Optimization of the application before launch
- Database optimization
- Effective caching
- Load balancing
- Auto-scaling
- Application monitoring
- Code optimization
- Resource optimization
Development teams should also establish performance benchmarks to ensure the money spent on development does not cause resources to be wasted, and budgets go beyond what's necessary.
The Role of Load Testing
Load testing is a development practice that helps simulate a large number of users before the application or advertisement campaign goes live and a large amount of actual traffic will be used. Instead of waiting to see bottlenecks after a product launch, developers can identify and nullify bottlenecks in a controlled environment.
Testing can reveal:
- The highest possible number of users simultaneously.
- The capacity of the server.
- Limitations and issues in the database.
- How difficult API requests become.
- How the application consumes memory.
- Application response time.
A reputable Mobile App Development Company may perform similar tests in situations where the backend services to the mobile and web application are shared. This is applicable when multiple applications rely on the same infrastructure.
Build for Scalability From the Beginning
Scalability should not be a consideration for a business when applications start showing problems. The design of an application should allow a business to scale easily to accommodate an increase in users without the need for major changes to the application.
An example of this would be scalability achieved through the use of Horizontal Scaling. This approach would utilize the Cloud to add Browser Servers when demand increases.
Scalable architecture preserves performance for users and allows for growth of a business without forcing the clients to suffer slower performance with more frequent downtime.
Monitor Performance Continuously
Even a well-optimized application will, with time, start having performance issues. New features, larger datasets, changing user behaviour, and increasing application demand all will introduce new bottlenecks, even in a well-optimized application.
Continuous monitoring helps development teams track:
- Response Time
- Memory and CPU usage
- Database performance
- Error Rates
- Level of traffic per server
- Availability of the servers
When unusual activity is detected, teams can investigate and resolve the problem before it becomes a major outage.
When Professional Development Support Makes Sense
High-traffic applications require more than an upgraded server. Developers need to understand the specific behaviour exhibited by application code, databases, and caching, along with APIs and infrastructure, when a high-traffic demand is placed on the application.
Having a Web and App Development Company with experience in adapting your website or application to your technological environment can allow you to identify and solve problems before they become expensive problems.
High traffic should never be the reason an application fails. Design flaws and weaknesses either in the infrastructure, database, application code, caching, or planning for scalability will manifest themselves and cause the application to fail.
Conclusion
High traffic is an opportunity for a business to grow. Performance problems are often caused by weak infrastructure, bad database and application design and code, poor caching, and bad planning for workload growth.
Most of these problems can be avoided by companies through application testing with an adequate workload, design planning, and implementing caching and traffic distribution along with consistent performance monitoring. The planning of a system's ability to grow is also important to the ease of growth in the future.
Whether you're building a customer-facing website or making a protected business-use system, performance must be functional and prioritized throughout the lifecycle of the project. With proper architecture and continuous improvements, a system designed to grow can support increased usage.
