Knative Architecture Setup - Activator Instability

[nardine-t]

Hey, we’ve been running into some unexplained instability with our Knative setup and are wondering whether our current architecture is ideal for production reliability.

We’re currently using Kourier along with Istio as an additional security layer. Is this a recommended setup, or would a simpler architecture—such as using Kourier alone—generally be preferable?

The recurring issue we’re seeing is that the Knative Activator appears to fail or become a bottleneck. When this happens, requests stop flowing end-to-end, even though the backend pods have already scaled up and there is still queued work waiting to be processed.

This has us questioning whether our current request path and scaling configuration are contributing to the problem. Has anyone encountered similar behavior?

We’d especially appreciate recommendations around:

• Whether Kourier + Istio is a reasonable architecture versus using Kourier alone
• Activator configuration or tuning
• Concurrency and target settings
• Ingress configuration/choice
• Scaling class or autoscaling adjustments
• Other approaches for ensuring traffic continues flowing reliably during load spikes