So far, the few HPA examples used a single custom metric to decide whether to scale the Deployment. You already know from the Chapter 1, Autoscaling Deployments and StatefulSets Based on Resource Usage, that we can combine multiple metrics in an HPA. However, all the examples in that chapter used data from the Metrics Server. We learned that in many cases memory and CPU metrics from the Metrics Server are not enough, so we introduced Prometheus Adapter that feeds custom metrics to the Metrics Aggregator. We successfully configured an HPA to use those custom metrics. Still, more often than not, we'll need a combination of both types of metrics in our HPA definitions. While memory and CPU metrics are not enough by themselves, they are still essential. Can we combine both?
Let's take a look at yet another HPA definition...