Knative Activator routing to old revisions and requiring component restarts

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Title: Knative Activator routing to old revisions and requiring component restarts

Hi, we’re running into some recurring instability with the Knative Activator.

One scenario we’ve observed is the Activator attempting to route traffic to a very old revision that is no longer deployed. When this happens, traffic stops flowing correctly even though the expected backend revision and pods are available.

So far, the only reliable way we’ve found to recover from this state is to restart all of our Knative components, after which routing begins working normally again.

Has anyone encountered similar behavior where the Activator retains or routes using stale revision information? We’d appreciate any guidance on what could cause this state, how to troubleshoot it, and whether there are configuration changes or known fixes that can prevent it from happening.

Start with the Knative Activator routing path and inspect its logs while reproducing traffic to an old revision. Determine how stale revision information is retained and what component restart clears it; document a reproducible case, relevant diagnostics, and a verified prevention or fix.