Typical memory utilization

What are the typical memory requirements for various parts of Istio as a cluster scales? I ask, as I’ve deployed on an 80-node cluster with ~350 namespaces, and in order to get the istio-proxy containers to even start, I need to give them a RAM limit of 1GiB (some seem OK with 512MiB). They then consume about ~416MiB, with occasional spikes up to ~760MiB.

On a 4-node test cluster with ~10 namespaces I do not see this behavior.

Take a look at the Performance Benchmarks mentioned in the docs. More particularly, the Performance Summary section.

You could also perform some tuning using Namespace Isolation via Sidecar resource that can minimize resource consumption across the mesh.