What is Chaos Engineering? How Does It Work?

The short answer: Chaos engineering is a software engineering process that intentionally introduces failures and errors to observe system behavior and test resilience. 

The primary goal of chaos engineering is to identify any weaknesses in a system before they cause problems in production environments. By simulating various adverse conditions, chaos engineering helps ensure that systems are robust, reliable, and, most importantly, capable of withstanding and recovering from real-world disruptions.

Chaos engineering is critical in the age of microservices and distributed cloud architectures. More people depend on these increasingly complex systems than ever before, but failures have become much harder to predict, and the impact of said failures has become extremely costly for the businesses that depend on them.

How Does Chaos Engineering Work?

Chaos engineering is a controlled and disciplined process for identifying failures before they become outages. It works by proactively stressing a system to see how it responds under various circumstances, making it possible to identify and fix failures ahead of time. This is done by “injecting” faults, failures, and errors into a system to see how it responds.

As a controlled process, it’s made up of four constituent parts that dev teams follow methodically to ensure the best results:

1. Hypothesis: Formulating a clear hypothesis about how the system should behave under specific failure conditions. The hypothesis acts as a prediction that sets expectations for the system's response to the induced failures.

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2. Testing: Introducing controlled failure scenarios into the system to test the hypothesis. Testing allows dev teams to observe the system's behavior under stress and validate whether it aligns with the hypothesis.

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3. Blast radius: The scope or extent of the impact that a chaos experiment is allowed to have on the system. Controlling the blast radius ensures that experiments do not cause widespread disruptions and can be safely managed.

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4. Insights: Analyzing the outcomes of the chaos experiments to gather valuable information about the system's resilience and areas for improvement. Insights help identify weaknesses, guide improvements, and enhance the overall robustness of the system.

Chaos Engineering in WireMock Cloud

WireMock Cloud combines API mocking and chaos engineering with its native Chaos functionality. By injecting failure states into mocked APIs, users can simulate complex failure scenarios and build more resilient API consumers. 

By introducing random chaos elements, WireMock Cloud users can easily stress-test their apps against the type of problems it’s likely to encounter in production environments. 

Learn more on our blog or watch Dan Perovich, WireMock's Head of Sales Engineering, demonstrate an end-to-end API resilience test in the WireMock Cloud Academy.