Intent

Quick startup times are favorable in Cloud environments to enable fast recovery and improve scaling.

Motivation

In Cloud environments it is accepted that a pod or container may crash - the more important principle is that it should recover fast. A faster startup time is beneficial in that case as it results in a smaller Mean Time To Recover (MTTR) and reduces the amount of user-facing downtime. Also, in case of request peaks, a reasonably short startup time allows scaling the deployment properly.

Structure

We simply stop a container of one of the pods in order to measure the amount of time until the pod is marked as ready again. Therefore, we ensure before stopping the container that the deployment is currently ready. If so, we stop the container and expect the number of ready pods to drop. Within a reasonable time (i.e. 60 seconds) the container should start up again and all desirable pods marked as ready.

Environment Example

A simple deployment with at least one pod at one running container is sufficient to try out the recipe. In our case, it is a container named toys-bestseller running a Java-based application.

Solution Sketch

• Kubernetes liveness, readiness, and startup probes