What is load testing?
Load testing is defined as a type of performance testing in which the performance of the system is determined under real-life load conditions. It helps in evaluating the behaviour of application when multiple users access it simultaneously.
Load testing is done to recognize:-
- Maximum execution capacity of the application
- Determine if the current infrastructure is sufficient to run the application
- Sustainability of maximum user load relative to the application
It’s a non-functional test. In software engineering, load testing is often used for client/server, web-based applications: intranet and Internet.
The number of concurrent users the application can support and the scalability that allows more users to access the application.
Why do you need Load Testing?
Some of the most popular websites experience severe downtime when they receive a lot of traffic. E-commerce sites invest heavily in advertising campaigns, but do not carry out performance testing to ensure optimal system performance when marketing brings traffic.
Let us understand this with an example:-
If you have hosted your website on shared servers, then whenever there is increase in traffic generated by your advertising campaigns, your site will not be able to keep up with the sudden surge in traffic and will crash.
Many sites suffer from delayed loading times when they find busy traffic.
- Most users click Leave after 8 seconds delay on the upload page
- $4.4 billion per year as a result of poor performance
This is where Load Testing comes to the rescue
- It gives you confidence in the system, its reliability and performance.
- It helps identify bottlenecks in the system in case of severe user pressure in a production environment.
- It provides excellent protection against poor performance and adapts to complementary strategies for performance management and monitoring of production environments.
What are the outcomes of Load Testing?
Load testing identifies the following issues before moving applications to market or production:-
- Response time per transaction
- Performance of system/database components under various loads
- Network latency between client and server
- Software design issues
- Server configuration issues such as web server, application server, database server, etc.
- Hardware limitation issues such as CPU maximization, memory limits, network bottlenecks, etc.
Load tests determine whether you need to adjust the system or modify hardware and software to improve performance.
Prerequisites for Load Testing
- Server Machines
- Disk Storage
- Load Machines configuration
- Network configuration
- Operating System
- Server Software
The primary metric for load testing is response time. Before starting the load test, you need to be sure:
- If response time has been measured and compared – Quantitative
- If the response time is applied to business process processes: Relevant
- If the response time is reasonable – Realistic
- Can you achieve the response time – Achievable
- If the response time can be measured with a tool or a stopwatch – Measurable
What are different strategies for Load Testing?
There are many ways to perform load tests. Here are some testing strategies −
Manual Testing: This is one of the strategies for performing load testing, but it does not produce repeatable results, does not provide a measurable level of stress for the application and is an impossible process to coordinate.
Internally developed testing tools: An organisation that recognises the importance of load testing can create its own tools to perform testing.
Open Source Testing Tools: There are several free open source testing tools. They may not be as complex as your payment counterparts, but if you have a budget, they are the best choice.
Enterprise-grade testing tools: Usually come with a capture/playback facility. They support a large number of protocols. They can simulate a large number of users.
How to perform load tests?
The load testing process can be briefly described as follows −
- Create a dedicated test environment for testing
- Determination of load test transactions for applications
- Prepare data for each transaction
- Need to predict the number of users accessing the system
- Determines the connection speed. Some users may be connected through a leased line, while others may use dial-up
- Identify the different browsers and operating systems used by users
- Configuration of all servers, such as web, application, and database servers
- Execution and monitoring of the test scenario.
- Compilation of various indicators
- Analysis results. To make recommendations
- Precision Adjustment Systems
- Perform the test again
Instructions for Load Testing
- Load tests should be scheduled after the application has stabilized.
- A large amount of unique data must be prepared in the data group
- The number of users must be determined by each scenario or script
- Avoid creating detailed logs to save io disk space
- Try to avoid downloading images on the site
- Consistency of response times over time should be documented and compared with several tests.
Load Test Tools:
Load ninja is radically changing the way we load the evidence. This cloud-based load test tool allows teams to instantly record and play complete load tests without complex dynamic correlation, and run these load tests at a scale in a real browser. Over 60%.
Neoload is an enterprise-class load testing platform designed for agile and developers. Neoload integrates with its continuous delivery pipeline to support performance testing throughout the software life cycle, from component testing to full system testing.
Load Runner is an HP tool for testing applications under normal and maximum load conditions. The load runner generates the load by creating virtual users that simulate network traffic.
The following are the advantages of load testing:
- Identification of performance bottlenecks before production
- Increase the scalability of your system
- Minimizes risks associated with system downtime
- Reduce the cost of failure
- Improve customer satisfaction
Disadvantages of load tests:
- Programming knowledge is required to use load test tools.
- The cost of the tool can be high because the price depends on the number of supported virtual users.
Load testing is defined as the type of software testing that determines system performance under actual load conditions.
Load testing typically improves the bottleneck of application performance, scalability, and stability before it can be used in production.
This test helps determine the maximum operating capacity of your application, as well as system bottlenecks.
Load tests are important because they can lead to financial losses if ignored.