Diving deep into spike testing: first aid for combatting unpredictable traffic patterns

Your software performs flawlessly in ideal conditions — pages load in the blink of an eye, transactions go off without a hitch, and all servers are reliable. However, the harsh reality is that normal conditions aren’t what counts when disasters hit.  

Let’s look at a few examples. Several years ago, during the post-New Year work rush began, users of a famous messenger faced notable slowdowns and errors as the service struggled to manage the surge in post-holiday visitor volume. Or another unpleasant incident. A company providing content delivery network and security services suffered an outage caused by a new rule in their security system, which led to high CPU usage and widespread 502 errors on various websites. What can we infer from this? 

A viral social media post, a successful product launch, or even celebrity shoutout can quickly flood your system with users without warning, giving you no time to prepare in advance. If your infrastructure isn’t prepared, it can face a complete crash, lost revenue, frustrated customers, and damaged trust. That’s why spike testing — checking that your systems can withstand sudden bursts of user demand — is crucial for any modern business. 

In this article, we’ll delve into the fundamental idea behind spike testing, its value for companies, and essential steps to effectively perform it. 

In the spotlight: what you should know about spike verifications 

Spike testing, being one of the types of tests conducted as part of performance testing, involves assessing how the system responds to sudden and sharp changes in the real-time user count, queries, and operations (referred to as “spikes”), and evaluating its capacity to recover and maintain fault tolerance. It aims to evaluate the system’s adaptability, confirming it can expand to meet the demand and contract once the spike fades. 

A well-developed load testing script emulates the rapid spikes on the system, which in the real world can lead to immediate unexpected system behavior. The described spike testing model helps teams of QA performance engineers quickly observe how — and whether — the system recovers once the load decreases. 

When do companies need spike testing? Well, the short answer is: “Companies need spike testing whenever there’s a possibility of sudden surges in traffic or system usage, whether anticipated or not.” Here are just few examples: 

• Scenario #1. Salaries hit employees’ accounts at the same time. As they flock to their banking apps to check their balances, the system gets hit with a jump in visitor activity. 

• Scenario #2. After rigorous testing, a company is convinced a new feature is ready for prime time, so they spread the word, inviting users to take it for a spin, thus provoking an abrupt load surge. 

• Scenario #3. Well-executed marketing campaigns, including special promotions, limited-time discounts, and new product launches, often create a ripple effect, drawing in not just immediate traffic but also boosting long-term user engagement. 

• Scenario #4. IT products that nudge users to hydrate, work out, or read can go through a classic boom-and-bust cycle, with users flooding in and then vanishing just as quickly. 

• Scenario #5. It’s almost the end of the working day, and all the employees of the company using your product start saving their work simultaneously before going home. 

By effectively managing sudden traffic surges, organizations across industries can reap significant business benefits. 

Spike testing applies pressure by simulating real-world surges, exposing weak links like disabling the message queue, misconfigured load balancer, ineffective system auto-scaling rules, or response time struggles. By uncovering problems early, organizations can fortify their applications, ensuring they don’t crack under pressure — an essential requirement for banking, healthcare, and real-time trading platforms. 

Additionally, identifying and fixing slowdowns from the start helps prevent customer churn and negative brand perception, leading to smoother user interactions. 

Organizations can leverage spike testing results to fine-tune their infrastructure investments. Whether it’s boosting server capacity, optimizing caching, or streamlining database performance, these insights help allocate resources more efficiently, cut unnecessary costs, and ensure seamless scalability as demand grows. 

For businesses that depend on their online presence for revenue, unexpected load surges can lead to costly downtime and lost sales. Spike testing acts as a safety net, uncovering vulnerabilities before they turn into full-blown failures. By proactively identifying weak points, businesses can prevent costly crashes, ensuring smooth, uninterrupted service that keeps sales flowing. 

Don’t let traffic spikes take you down! Talk to a1qa’s specialists for a tailored testing strategy. 

Nail your spike testing: 6 steps to get it right 

Now, we’d like to walk you through the essential steps to conduct an effective spike test and ensure your software remains resilient during a big sale, a viral event, or any other high-traffic occasion. 

1. Analyze the software  

Before testing, a comprehensive analysis of the software and its expected load is essential. This understanding guides the creation of a practical and effective test strategy. 

Software applications vary in nature—some emphasize content, others facilitate transactions, and some depend on real-time interactions. For instance, online retail platforms may encounter high traffic volumes during promotional events, whereas streaming services might experience surges upon new episode releases.  

By analyzing user behavior and identifying key functions and system architecture, teams can set performance benchmarks and realistic testing goals. 

2. Equip yourself with optimal tools 

Selecting the right testing solution is crucial for conducting an effective spike test. The selection process should be thorough and consider multiple factors, among which I’d mention: 

• Budget. While open-source solutions such as JMeter or Gatling are cost-effective, they often require additional setup and customization. In contrast, commercial solutions such as LoadRunner and BlazeMeter provide advanced capabilities and enterprise support, though at a premium price.  

• Ease of use. While some testing tools require scripting knowledge, others prioritize usability with graphical interfaces. For instance, LoadRunner is ideal for teams with limited coding skills, whereas JMeter is better suited for those who prefer script-based flexibility. 

• Configurability. An effective spike testing tool should simulate traffic surges by generating significant loads. Some tools allow creating a very flexible model and load profile, while others offer basic settings only. 

• Realistic user simulation. Some tools can cover only separate APIs, while others can emulate the real user behavior on the HTTP requests level by reproducing real users’ actions in the system.  

By evaluating these criteria based on their unique requirements, organizations can choose a tool that delivers precise and actionable insights into system performance under sudden load surges.  

3. Get prepared 

Setting up a separate test environment that replicates the production one is vital to ensure spike tests are meaningful and indicative of the system’s performance. Such similarity helps reduce the risk of failures or outages in the production. Prior to testing, QA performance engineers in collaboration with DevOps or development teams should review factors like CPU, RAM, disk space, network bandwidth, OSs, software versions, and configurations to ensure the test environment is properly configured. 

4. Conduct tests 

Now, it’s time to apply a sudden and extreme load to the system. During testing, it’s wise to evaluate a range of patterns to ensure your software can handle various traffic surges. Some spikes emerge suddenly, while others grow steadily over time. By testing both rapid bursts and gradual increases, project teams can better understand how well the system adapts to different escalation scenarios. Additionally, it’s important for teams of QA performance engineers to pay attention to how the system behaves after the traffic surge ends, as a delayed recovery can still affect user experience, even after traffic returns to usual levels. 

5. Examine outcomes 

During test execution, it’s important to investigate the system behavior using a real-time monitoring. After running the spike test, ensure you analyze the data and match it against your performance benchmarks to see how the system responds to extreme loads. Look for any unexpected behaviors and failures and make note of key results like the peak load before failure, performance slowdowns, recovery time, and any other important observations. This lays the foundation for a further important step. 

6. Pursue excellence 

Based on the findings from the test results, it’s important to focus on optimizing system performance to effectively handle spikes. For example, enhancements may include boosting server scalability with auto-scaling, refining backend logic to manage sudden traffic surges, or using caching to reduce the need for repeated data retrieval from diverse sources. 

In a nutshell 

Spike testing gauges how an IT product behaves when subjected to sudden and extreme increases or decreases in load, thus helping organizations across industries ensure software’s boosted robustness, improving end-user reviews, decreasing operational expenditure, and ensuring business continuity regardless of the circumstances. 

To maximize spike testing efficiency, companies can carefully analyze the expected load, choose project-specific tools, dedicate effort to setting up a test environment, run verifications, analyze results, and do not bail on further optimization. 

Are you facing system slowdowns? Contact a1qa’s experts to get professional consultation and support.