Frédéric Gaudet, Senior SRE @ BlaBlaCar, explains his testing approach for validating Istio's pod warm-up feature before production deployment.

He reveals a critical insight about the interaction between pod warm-up and Horizontal Pod Autoscaler (HPA). When a new pod warms up and receives reduced traffic, that traffic gets redistributed to existing pods, potentially triggering CPU spikes. However, he discovered that keeping warm-up duration under the HPA trigger time (2 minutes warm-up vs 5 minutes HPA trigger) prevents instability.

Watch the full episode: https://ku.bz/grxcypt9j