The foundation of performance testing is workload modeling. It involves developing an extensive schema that specifies what needs to be tested, how to split up the workload, and when to use it. Creating a workload model that accurately represents real-world usage scenarios is the goal. While this is an important phase in the performance testing process, it is sometimes overlooked how important a solid workload model is. We’ll talk about workload modeling in this post and why it’s important to include this step in your projects.
Understanding the Significance of Workload Modeling
According to recent surveys, 40% of enterprise projects indicate hardware overuse and application performance bottlenecks, which result in budget overruns. These bottlenecks are frequently caused by improper performance requirement collection methods. Many businesses deal with similar issues:
- Misaligned User Load. The performance test team conducts tests that don t match with the production peak user load. This misalignment can lead to severe bottlenecks when more users access applications than the anticipated capacity.
- Inadequate Real-World Correlation. When the load profile doesn t align with real user behavior, system performance can deteriorate before reaching the peak load indicated by testing. For instance, assuming most customers check out as guests, but in reality, 80% first log in before checking out. Hence, the system might work slowly due to authentication API overload, even if the main server hasn t reached its peak of power.
- Overallocation of Hardware. If current performance test results don t meet with Service Level Agreements (SLAs), organizations allocate more hardware, leading to unnecessary expenses.
Performance testing must place a strong emphasis on developing a solid workload model in order to successfully handle these issues. During the design stage of performance testing, workload modeling is an essential component that helps companies to build realistic scenarios that include actual user activity, batch procedures, and large loads from other systems via APIs. Professional services may greatly improve the accuracy and dependability of your tests, ensuring that any possible bottlenecks are found and fixed, for those in need of experienced load and performance testing.
Workload Modeling in Performance Testing
One of the most important components of the performance testing planning stage is workload modeling. Its purpose is to reveal the actual peak user load and practical business circumstances.
Analysts and functional testers have historically assisted performance testing teams in gathering crucial data. Teams examine statistics from databases and logs, or in their absence, business projections, to ascertain how frequently processes occur.
However, this method is frequently laborious and might not produce a precise representation of user behavior in a live production environment. A more effective approach would be to start the process with a testing technique that works well with production data, extracting information from server logs, and gaining access to databases.
Designing an Accurate Workload Model
When creating a precise workload model, performance testers ought to take into account the subsequent elements:
- Emulating Real User Behavior. A robust workload model should replicate the real user and transaction load experienced in production, incorporating elements such as caching and think time behavior.
- Geographical Considerations. It s essential to consider the global distribution of users and the potential variation in test data across different regions.
- Understanding Business Flows. Acquiring a deep understanding of business processes and end-user workflows is essential to mirror real-world usage accurately.
- Identifying Critical Transactions. Close collaboration with business stakeholders helps to pinpoint essential transactions used in real-world scenarios. These often encompass not only business-critical operations but also the most frequent and resource-intensive functions, such as various jobs, reports, and downloads.
Metrics in Workload Modeling
A number of metrics are taken into consideration when creating a workload model for performance testing. Performance testers can better develop scenarios that accurately reflect real-world conditions with the use of these measures. The following are important workload modeling metrics:
- Number of Users. This metric represents the expected user load on the server during the test.
- Iterations per Hour. It indicates how many iterations a user needs to complete in the test duration.
- End to End Response Time. This metric is both calculative and targeted, aiming to achieve specific response time goals.
- Number of Transactions. It involves calculating the number of transactions that occur during the test.
- Pacing. Pacing is another calculative metric that determines the time intervals between user actions.
- Think time. Like pacing, timer is a calculative metric that simulates the time users spend thinking between actions.
- Throughput. This targeted metric focuses on the rate at which requests are made to the server.
- Individual Page Response Time. This metric targets the response time for individual pages or components within the application.
It is necessary to comprehend these metrics and how they relate to actual user behavior in order to create a workload model that works.
The Role of Performance Testers
An essential part of the workload modeling process is performed by performance testers. Their job is to create the performance test scenario according to the Performance Test Plan’s detailed instructions. Achieving the intended performance testing objectives is the ultimate goal, regardless of the complexity of computations and metrics involved in workload modeling during the performance testing process.
A Deeper Dive into Workload Modeling
Workload profiles that mimic actual usage circumstances make up a workload model in performance testing. These profiles, which incorporate various user kinds and attributes, are meant to simulate actual usage scenarios. Performance testers should think about several important questions in order to develop an efficient workload model:
1. Which User Actions Can Be Included in the Profile?
This inquiry focuses on figuring out what precise actions a user can take when using the web application. In online banking apps, for instance, tasks could include paying bills, checking account balances, transferring money between accounts, viewing transaction histories, and logging out. To create user profiles, it is necessary to identify these actions.
2. What Defines User Profiles in the Application?
User profiles, which simulate common use cases or scenarios of actual users engaging with the application, are a crucial component of a workload model used in performance testing. Even though Black Friday sales are a well-known high-intensity event, workload profiles can vary, involving both variations in intensity and types of operations undertaken. Take online banking as an example, where user activity on payday could differ greatly from other days.
3. What Actions are Performed by Users in Each Profile?
It’s critical to comprehend the precise behaviors that consumers take within each profile. For example, you may observe that visitors to a news website frequently read three stories in a single session. This analysis counts the number of times each activity is completed in a single session by breaking down each action within a user profile.
4. What Is the Average Time Between User Actions?
Think time is the amount of time visitors spend on a page between two consecutive actions. This time may change based on variables such as the complexity of the page. A login page, for instance, might require less thought time than an order placement page where consumers must enter credit card information.
5. How are User Profile Scenarios Expected to Be Distributed?
Knowing the ratio of operations makes it simple to control the load during testing, modifying intensity in a proportionate manner. One can approximate or quantify how different user profiles distribute business actions. For instance, a typical e-commerce application usage pattern would include 77% of users browsing, 20% searching, and 3% placing orders. The exact percentage should correctly reflect actual transaction patterns and be in line with the distinctive features of your website, business, and user behavior.
6. How Does the Number of Logged-in Users Vary Over Time?
It is essential to comprehend the variations in the user base by day of the week, time of day, and other variables. Variations in user load occur in real-world deployments, and this should be taken into account when creating the workload model for performance testing. A dating website, for instance, would have a consistent volume of traffic during the day, a peak close to closing time, and a higher peak in the run-up to Valentine’s Day.
7. What is the Peak Concurrent User Capacity?
Peak concurrent user capacity is the most concurrent visitors your website can support at once. You may use requirements documents or marketing forecasts for new applications. Analyze a combination of analytics data, business projections, and server logs to obtain insights for current applications.
8. What is the Test Duration?
The test length varies according to the features of your application; it might be as little as 20 minutes or as long as many days or weeks. Your testing goals, such as evaluating login procedures or spotting memory leaks over time, will determine which option is best.
Making ensuring your workload modeling process takes these factors into account will guarantee that your load testing accurately resemble actual usage patterns. This alignment improves the precision of your performance testing and offers insightful information about the capabilities of your application.
Conclusion
In performance testing, workload modeling is essential to accurately emulating real-world circumstances. It is the foundation for understanding user behavior, creating relevant situations, and simulating their various aspects. Testers can make sure that web applications are scalable and reliable by carefully examining metrics and creating workload profiles. Workload modeling is more than just a series of procedural procedures; it is the essential component that makes performance testing yield meaningful and practical insights.