Understanding Stress Testing | What Is Stress Testing ?

What is Stress Testing in Software Testing?

Stress testing is a technique used in software testing to determine how the software stands up under conditions far exceeding typical, normal operation. It is especially important for critical software but applies to all types of software. Stress testing emphasizes robustness, availability, and error handling under a heavy load rather than what is correct behavior under normal situations. Stress testing is defined as a type of software testing that verifies the stability and reliability of the system. This test particularly determines the system on its robustness and error handling under extremely heavy load conditions. It even tests beyond the normal operating point and analyses how the system works under extreme conditions. Stress testing is conducted to ensure that the system will not crash during crunch situations. Stress testing is also referred to as Endurance Testing or Torture Testing.

Characteristics of Stress Testing:

Identifying Risk: One of the main objectives of Stress Testing is to detect and assess possible hazards and vulnerabilities of the system.
Quantitative and Qualitative Analysis: While numerical data is often key, it is also essential to comprehend the qualitative characteristics of the response and potential weak points of the system.
Variable Parameters: Stress testing has changing variables, such as interest rates, market conditions, transaction volumes, and external impacts.
Cross-Functional Involvement: Many departments within an organization must work together and be part of the stress testing. This cross-functional approach ensures that the stress testing procedure benefits from a broad range of viewpoints and skills.
Open and Honest Communication: There needs to be open and honest communication on the aim, approach, and results of the test procedure.

Need for Stress Testing:

To provide for sudden traffic surges: Stress testing must be run to prepare for sudden increased traffic. For instance, when there is a great sale announced on the e-commerce website, there is a sudden increase in traffic. Failure to plan for such needs may result in losing revenue and reputation.
Error messages in stress conditions: Stress testing is required to be carried out to determine whether the system is able to display the appropriate error messages when operating under the stress conditions.
Abnormal system behavior: Stress testing has to be carried out to ensure whether the system can continue functioning under abnormal conditions.
Prepare for stress conditions: Stress testing helps to ensure there are sufficient contingency plans in case of sudden failure due to stress conditions. It is better to be prepared for extreme conditions by executing stress testing.

Purpose of Stress Testing:

Information from failure analysis: The purpose of Stress Testing is to ascertain the behavior of the application after failure, and that the software should give out the right error messages during extreme conditions.
Recovery of the system after failure: Stress testing tries to guarantee that there are recovery plans available so that the system recovers from failure.
Hardware issues and data corruption issues: Stress testing helps in detecting hardware issues and data corruption issues.
Detection of security vulnerabilities: This helps in detecting the vulnerabilities of the security system that can be penetrated due to constant peaks in load and compromise the system.
Data integrity: This helps in deducing whether the data integrity of the application is there through the extreme load, meaning that the data should be available even after a failure.

Stress Testing Process:

The 5 steps in the process of Stress Testing are:

1. Planning the stress test: This step involves gathering the system data, analyzing the system, and defining the stress test goals.

2. Script Creation: This step involves creating the automation scripts for the stress test and generating the test data for the stress test scenarios.

3. Script Execution: This step involves running the automation scripts and storing the stress test results.

4. Result Analysis: This phase involves analyzing the stress test results and identifying bottlenecks.

5. Tweaking and Optimization: This step includes fine-tuning the system and optimization of the code with the goal of meeting the desired benchmarks.

Types of Stress Testing:

Server-Client Stress Testing: Server-client stress testing is the one carried out across all the clients from the server.
Product Stress Testing: Product stress testing relates to discovering defects of any type related to data locking and blocking, network issues, and performance congestion within a software product.
Transactional Stress Testing: Transactional stress testing involves performing tests on one or more transactions between two or more applications. It fine-tunes and optimizes the system.
Systematic Stress Testing: Integrated testing that integrates systematic stress testing to test across multiple systems running on the same server. It identifies defects when one application blocks another application's data.
Analytical Stress Testing: Analytical or exploratory stress testing tests systems with unusual parameters or conditions that will likely occur during real scenarios. This test finds defects that occur in unusual scenarios, such as many users logging in at the same time or a database going offline when it is accessed from a website.
Application Stress Testing: This application, which is also known as product stress testing, focuses on the identification of the performance bottlenecks and network issues within a software product.

Tools Used in Stress Testing:

Jmeter: Apache JMeter is a stress-testing tool that is an open-source, pure Java-based software, used to stress test websites. This Apache project is used for load testing to analyze and measure the performance of a variety of services.
LoadNinja: LoadNinja is a stress-testing tool developed by SmartBear that enables users to develop codeless load tests, replacing load emulators with actual browsers, and enables achieving high speed and efficiency in browser-based metrics.
WebLoad: WebLoad is a stress-testing tool that combines performance, stability, and integrity as a single process for the verification of mobile and web applications.
Neoload: Neoload is a powerful performance testing tool that simulates a large number of users and analyses the server's behavior. It is designed for both mobile and web applications. Neoload supports API testing and integrates with different CI/CD applications.
SmartMeter: SmartMeter is a user-friendly tool that helps to create simple tests without coding. It has a graphical user interface and has no necessary plugins. This tool automatically generates advanced test reports with complete and detailed test results.

Metrics of Stress Testing:

Metrics are used to evaluate the performance of the stress and is usually carried out at the end of the stress scripts or tests. Some of the metrics are given below.
Pages per Second: Number of pages requested per second and number of pages loaded per second.
Pages Retrieved: Average time taken to retrieve all information from a particular page.
Byte Retrieved: Average time taken to retrieve the first byte of information from the page.
Transaction Response Time: Average time taken to load or perform transactions between the applications.
Transactions per Second: It counts the number of transactions loaded per second successfully and also counts the number of failures that occurred.
Failure of Connection: Counts the number of times that the client faced connection failure in the system.
Failure of System Attempts: Counts the number of failed attempts in the system.
Rounds: Counts the number of test or script conditions executed by clients successfully and also keeps track of the number of rounds that failed.

Stress Testing Benefits:

- Detects behavior: It detects the behavior of the system after a failure and makes sure the system recovers quickly.

- Ensures no security breaches are caused: The system makes sure that system failure does not cause a security issue.

- Makes the system function in every situation: It makes the system work under normal as well as abnormal conditions in a correct and fitting way.

- Benefits decision-making: The information from stress testing can be used in the decision-making process of the organization.

- Boosts stakeholder confidence: With clear information on the outcomes of stress tests, the confidence of the stakeholders has gone up. Organizations that take an active interest in risk management are highly respected by investors, customers, and others in general, since it fosters confidence and credibility.

Stress Testing Limiting Points:

- Complicated Manual Stress Testing Process: A manual stress test is a complex process that needs more time to finish and is difficult to do.

- Good scripting knowledge: Great scripting knowledge needs to be in place to implement the script test cases for the particular tool.

- Requirement of External Resources: There is an opportunity for more resources and time with external resources for the implementation of stress testing.

- The licensed stress testing tool charges more than average: In the case of a licensed stress testing tool, the cost comes at a premium.

- Additional tool required in the case of open-source stress testing tool: There is an extra need for a load testing tool in some open-source tools for the setup of stress testing.

- Improper script or test case implementation: Only in the case of improper implementation of the stress scripts or test cases, there will be a chance for wastage of resources and wastage of time.

Here's the reference video for you to watch and better understand the topic:

Conclusion:

Stress testing is an important, proactive way to risk manage the business by letting it know how it will respond in such conditions and where its weak points are. The method is putting financial institutions, systems, or processes through harsh conditions to find vulnerabilities, evaluate risks, and improve overall capability.

Stress testing is usually used as an element of performance testing with an aim of determining the stability of a system in case of volatile situations. Stress testing is a process of deliberately stressing the system to its utmost capacity as in forcing high traffic through the application This makes it easier to tell how the application responds to pressure, and how it deals with such conditions that it was never programmed to encounter. Acceptance tests of this kind are critical to ascertain the stability of the system, its ability to effect an error-free rollback, and to deliver a high-quality performance to the user in a shakiest of environments.

Stress testing risk management solution enables organizations to identify performance constraints and optimally prepare for increased workloads. This not only assist to overcome future possible downtimes and low performance but also help to gain confidence level among the stakeholders and users of the system regarding its stability in real environment. In short, stress testing is one of the necessary and effective practices in the development of an adequate quality, reliable, and user-friendly application for any organization.