throttling

Rapid function scaling can overwhelm a shared dependency. Concurrency limits, reserved capacity and queue buffering are the containment toolkit.

The pair everyone configures and few can explain. QoS hints at eviction risk, but usage versus requests and Pod priority determine node-pressure ranking, and CPU and memory behave completely differently when you exceed them.

Every SDK fetches its credentials from a link-local metadata endpoint with a modest request budget. Enough containers refreshing at once and the endpoint starts refusing, which the SDK reports as an auth problem.