How Chaos Testing Improves Your Software’s Resiliency

You want your software to tolerate failure, while also providing appropriate quality of service level. But in today’s complex and distributed software systems, more than one thing can fail at the same time. To truly understand how a software application will work for users in real-world scenarios, you need to find out what happens when things go wrong.

Chaos testing and chaos engineering provide a systematic approach to this issue by introducing failure and measuring the software’s ability to cope, resulting in a deeper understanding of its resilience and durability. It helps by simulating the conditions needed to uncover issues and find performance bottlenecks that can be challenging to identify in distributed systems. This method is quite effective in preventing downtime or production outages before their occurrence.

Chaos testing can offer valuable intelligence on a software’s ability to withstand real-life conditions, where things don’t always go as planned. Combined with the DevOps build-test-release cycle’s continuous integration and development pipelines, recovery times will improve and the software becomes more stable.

What Is Chaos Testing?

Chaos testing refers to a systematic process where independent software testing professionals will crash an application on purpose. Random failures are introduced into the production system. As a result, the testing procedure can measure the software’s ability to recover and evaluate the impact of that failure. Chaos testing can significantly improve confidence and reduce recovery times as improvements are made.

Key Benefits of Chaos Testing

Chaos testing offers several advantages for the software development process:

Key Benefits of Chaos Testing
  • Determination of how common failures could result in downtime
  • Methodology to strengthen software against those failures
  • Reduced revenue loss due to downtime
  • Improved user experience
  • Greater confidence in the resiliency of the system

What Is Chaos Monkey?

Developed by Netflix engineers, Chaos Monkey tests a software application’s resiliency and recoverability in a cloud network. “The name comes from the idea of unleashing a wild monkey with a weapon in your data center (or cloud region) to randomly shoot down instances and chew through cables — all the while we continue serving our customers without interruption,” Netflix explained.

For example, these tools would intentionally introduce failures like disabled servers, network failures, dependency failures, latency, memory malfunction, etc. Chaos Monkey is now part of a larger suite of tools called the Simian Army, which is designed to simulate and test responses to various system failures and edge cases.

Pros and Cons of Chaos Testing

The introduction of failures to test software’s resiliency offers both pros and cons.


  • A better understanding of software’s reaction to failure 
  • Opportunity to make improvements
  • Fewer failures for end-users
  • Improvement in system availability
  • Reduction of outages and the resulting losses in revenue
  • Strengthened disaster recovery methods
  • More reliable software applications


  • Associated costs of testing and refinement
  • Improper application of chaos testing principles
  • Not supported by all development methodologies

Key Principles of Chaos Engineering

The principles of chaos engineering follow the scientific method of establishing facts through testing and experimentation:

Principles of Chaos Engineering
  1. Define a system’s normal behavior: Determine how software stability will be defined and identify measurable outputs.
  2. Develop a hypothesis: Create a hypothesis on what actions will affect the software’s stability.
  3. Apply failure: Develop and conduct experiments that introduce failure into the system.
  4. Observe results: Gather data and compare results before and after the failure is introduced.

Using chaos engineering to improve your software’s resiliency can result in a more stable application that provides a better user experience. Contact the independent software testing experts at InApp to learn how we can help you.