The History of Canaries in the Cloud

Since there have been computer networks — which is to say, since the debut of ARPANET in 1969 — there have been network reliability problems. Finding those problems before they impact end-users has long been a priority of any organization seeking to deliver an excellent user experience and make good on service level agreements (SLAs).

Keep reading for a look at what canary apps are, why they are important in the history of networking and the cloud, and how they’re poised to grow even more crucial as network and cloud architectures increase in complexity.

What Are Canary Applications?

With canary applications, teams can easily validate whether applications process requests in the time period required by an SLA, for example, or whether changes to a network’s configuration cause a slowdown in traffic flows.

How Do Canary Apps Work?

To deploy a canary app, you first create a simple application using a language like Python or Java that performs the key functionality you want to test. Then, you package and run the app. Once it’s running, you watch and wait, checking whether the app does the things it is supposed
to do.

This is a simplistic example. A real canary app might do more than just send a few packets; it would allow you to validate that all key aspects of application functionality — deployment, opening up a connection, sending and receiving traffic, closing a connection, and then repeating as necessary — work properly.

Canary Apps vs. Canary Deployments

Importantly, canary applications are different from canary deployments, although both concepts are related.

In contrast, a canary application isn’t a production application (although it runs in the same environment as production apps) and it’s not directly exposed to end-users. Instead, the purpose of a canary app is to give IT operations teams the ability to discover potential problems by detecting issues with the canary app instead of production apps. If some part of the canary app fails, it’s likely that equivalent functionality in the actual production app will also fail, so engineers will know that they need to investigate and fix the issue before it impacts real end-users.

Canary Apps in the Past, Present, and Future of the Cloud

The ability to validate whether applications and network connections work as expected is valuable in any type of environment that involves a computer network. For that reason, as noted above, service providers have long turned to canary apps to test networking configurations.

But with the advent of cloud computing, canary apps became even more valuable. In the cloud, networking configurations tend to be more complex; it’s common to have many software-defined virtual networks running on top of a physical network. In addition, your ability to monitor the network directly may be limited in a cloud computing environment because you can’t access physical network infrastructure. You can only test and monitor network behavior using whichever tools and data sources your cloud provider supports.

In that context, canary apps are a great way of testing whether a cloud network works properly. They don’t require any special monitoring tools, IAM configurations, or cloud services; all you need in order to use a canary app is a simple app and a cloud environment to deploy it in.

In the future, canary apps are likely to become even more important because cloud networks will grow even more complex. As more and more workloads shift into distributed, cloud-native environments, organizations end up with yet more software-defined and overlay networks. Canary apps offer a simple way of testing whether the network works as required in a cloud-native environment: instead of sifting through reams of network logs and trying to puzzle out how the network configuration actually works, you can simply deploy a canary app and see what happens to check whether connections can open and packets can move as needed.

Conclusion

Cloud networks are complex, and they’re only going to get more complex as technologies evolve. That’s why canary applications will remain a key resource for teams that need to verify that network configurations support their workloads. Canary apps aren’t the only way to test and monitor a cloud network, but they are arguably the simplest — and that feature makes them all the more valuable in a world where taming complexity is often the top priority of developers and IT teams.

Chris Tozzi has worked as a Linux systems administrator and freelance writer with more than ten years of experience covering the tech industry, especially open source, DevOps, cloud native and security. He also teaches courses on the history and culture of technology at a major university in upstate New York.

Originally published at https://blog.cloudcanaries.com.