KubeCon + CloudNativeCon Europe 2019

A core component of serverless platforms is scale-to-zero functionality which provides users with near 0 application cost when idle. With this comes the dreaded cold-start problem: When a user's application is not in use for an extended period an activating request can take significantly longer to complete. Knative is no different in this respect and until recently our cold-start time was measured in seconds due to the cost of Kubernetes deployments. Recently, a large effort was undertaken to improve this delay and the result is a system which scales Kubernetes deployments up from 0 in nearly a second. We will dive deep into what actually goes on inside Kubernetes when a deployment is scaled up, how we determined where time is spent, and then some of our novel techniques to drastically speed up this process.