oving the system in many ways.</p>
<h3 id="config-canaries">Config canaries</h3>
<p>Mixer is highly scaled so it is generally resistant to individual instance failures. However, Mixer is still susceptible to cascading failures in the case when a poison configuration is deployed which causes all Mixer instances to crash basically at the same time (yeah, that would be a bad day). To prevent this from happening, config changes can be canaried to a small set of Mixer instances, and then more broadly rolled out.