Canary testing: Everything you need to know

What is canary testing?

Canary testing is a type of deployment strategy that involves rolling out new changes or updates to a small subset of users before releasing them to the entire user base. 

The idea is that by releasing product changes to a small group first, you can monitor any behavior and performance changes and catch any issues or bugs before they affect a larger audience.

The approach is named after the canary in a coal mine, which was used to detect dangerous gasses before miners were affected. Similarly, canary testing aims to detect and isolate any issues or bugs in the new code changes before they impact the entire system or user base.

How does canary testing work?

Canary testing works by rolling out changes or updates to a small subset of users, known as the "canary group," before releasing them to the wider audience. Here's how it typically works:

1. Select the canary group: The canary group is typically selected based on specific criteria, such as geographic location, device type, or user behavior. This group should be representative of the wider audience and large enough to provide meaningful feedback.
2. Release the changes: The changes or updates are then released to the canary group while the rest of the user base continues to use the old version. This allows organizations to monitor the behavior and performance of the canary group and detect any issues or bugs before they affect the larger audience. This is most commonly done using feature flags via a feature management solution.
3. Monitor the canary group: Organizations closely monitor the behavior and performance of the canary group using metrics and monitoring tools. This can help identify any issues or bugs that need to be addressed.
4. Address any issues: If issues are identified during the canary testing phase, organizations quickly address them before they impact the wider audience. This may involve rolling back the changes or making additional fixes.
5. Release to the wider audience: Once the changes have been tested and any issues have been addressed, they can be released to the wider audience with confidence.

By following this process, teams can catch and address issues early on and increase confidence in the quality and reliability of their products or services.

Benefits of canary testing

There are several benefits to canary testing including:

• Risk mitigation: By releasing changes to a smaller group first, canary testing reduces the risk of negative impacts on a wider audience. Organizations can catch and address issues or bugs early on, before they become larger problems.
• Increased confidence: Provides confidence that new changes or updates are stable and reliable before releasing them to the entire user base to help build trust with users and stakeholders.
• Improved testing: Allows for targeted testing on a specific group, which can provide insights into how the changes perform in real-world scenarios. This can improve the overall testing process and help identify areas for improvement.
• Faster release cycles: By catching and addressing issues early on, canary testing can help reduce the time it takes to release changes or updates. That way organizations can move faster and stay ahead of the competition.

Canary testing can help teams improve the quality and reliability of their products or services while reducing risks and increasing confidence.

Disadvantages of canary testing

While canary testing can provide significant benefits to organizations, there are also some potential disadvantages to consider. 

• Increased cost: Can be resource-intensive, requiring additional time, personnel, and infrastructure. This can add to the overall cost of development and testing.
• Increased complexity: May be complex to set up and manage, requiring careful planning and execution to ensure that it is effective. 
• Limited sample size: Typically involves testing changes on a small, representative group before releasing them to a wider audience. While this can help identify issues early, it also means that the sample size is limited, which may not capture all potential issues.
• Inaccurate representation: If the canary group is not representative of the wider audience, canary testing may not accurately reflect how the changes will be received by the entire user base

While canary testing can provide significant benefits to organizations, it is important to carefully consider the potential disadvantages and plan accordingly to ensure that it is effective.

Best practices for the implementation of canary testing 

Implementing canary testing requires careful planning and execution. Here are some best practices for getting started.

Define clear goals. Before implementing canary testing, it's important to define clear goals and objectives. This can help guide the testing process and ensure that the testing is focused on achieving specific outcomes.

1. Define clear goals. Before implementing canary testing, it's important to define clear goals and objectives. This can help guide the testing process and ensure that the testing is focused on achieving specific outcomes.

2. Select a representative canary group. The canary group should be representative of the wider audience and large enough to provide meaningful feedback. It's important to select the canary group carefully and ensure that it is diverse enough to capture a wide range of user behaviors.

3. Establish a monitoring plan. Organizations should establish a monitoring plan that includes specific metrics and tools to track the performance and behavior of the canary group. This can help identify issues or bugs early on and ensure that they are addressed quickly.

4. Gradual rollout. When rolling out changes to the canary group, it's important to do so gradually. This can help minimize the impact of any issues or bugs and allow organizations to make quick adjustments as needed.

5. Automated rollback. Organizations should have an automated rollback plan in place in case any issues or bugs are detected during canary testing. This can help minimize the impact on users and ensure that the product or service remains stable and reliable.

6. Communicate with stakeholders. It's important to communicate with stakeholders, including users and internal teams, throughout the canary testing process. This can help manage expectations, build trust, and gather feedback that can be used to improve the product or service.

By following best practices and being thoughtful about the testing process, organizations can minimize risks, increase confidence, and improve the quality and reliability of their products or services.

Common challenges with canary testing and how to avoid them

While canary testing can be a highly effective way to identify issues and improve the quality of products or services, there are some common challenges that organizations may encounter during the testing process. 

Identifying a representative canary group

One of the key challenges in canary testing is identifying a canary group that is representative of the wider audience. 

To address this challenge, organizations should carefully evaluate the demographics and behaviors of potential canary users and select a group that is diverse and can provide meaningful feedback.

Defining clear metrics 

In canary testing, it's important to define clear metrics that can be used to track the performance and behavior of the canary group. If these metrics are not well-defined, it can be difficult to assess the success of the testing process. 

To address this challenge, organizations should work to define clear and measurable metrics before beginning canary testing.

Maintaining consistency

In some cases, it may be difficult to maintain consistency between the canary group and the wider audience. This can lead to inaccurate or misleading results. 

To address this challenge, organizations should carefully control the rollout of changes to the canary group and ensure that they are representative of the wider audience.

Overcoming bias 

Another common challenge in canary testing is bias, which can arise from a variety of factors, such as the preferences of the testing team or the limitations of the testing environment. 

To address this challenge, organizations should work to minimize bias by using randomized testing methods and ensuring that the testing environment is as realistic as possible.

Managing expectations

Finally, managing expectations can be a challenge in canary testing. It's important to communicate clearly with stakeholders and ensure that they understand the limitations and goals of the testing process. 

To address this challenge, organizations should work to build trust and transparency with stakeholders and communicate regularly throughout the testing process.

By being aware of these challenges and taking proactive steps to address them, organizations can improve the quality and reliability of their products or services and achieve their testing goals more effectively.

Canary testing vs. A/B testing

Canary testing and A/B testing are two different testing methods used in software development to assess the impact of changes and improve product quality. Here's a comparison of the two.

Canary testing is generally better suited for assessing the impact of specific changes and detecting issues early, while A/B testing is better suited for comparing different variables and determining which one is more effective.

Getting started with canary testing

Canary testing is a valuable testing technique that allows developers to test changes on a small subset of users before rolling them out to a wider audience. 

It helps reduce risk, detect issues early, and improve the overall quality of software products. While canary testing does have some disadvantages, such as the need for careful planning and monitoring, these can be mitigated through best practices and the use of appropriate tools. 

By incorporating canary testing into their development process, teams can improve the reliability, performance, and user experience of their products.

To learn more about how Kameleoon can help your team with canary testing, check out our Feature and Full Stack experimentation solution.