Test releases with canary deployments
Improvements in best practices for deploying have greatly improved the stability of deploys over the years. Automating the repeatable steps, standardizing the way our application interacts with the runtime environment, and packaging our application code with the runtime environment have all made deployments safer and easier than they used to be.
Introducing new code to a production environment is not without risk, however. All the techniques discussed in this chapter help prevent predictable mistakes, but they do nothing to prevent actual software bugs from negatively impacting users of the software we write. Canary deployment is a technique for reducing this risk and increasing confidence in new code that is being deployed to production.
With a canary deployment, you begin by shipping your code to a small percentage of production traffic. You can then monitor metrics, logs, traces, or whatever other tools allow you to observe how your software is working...