- The incident involved intermittent failures in a search backend triggered by a slow dependency, not CPU throttling.
- The false root cause (CPU throttling) was initially appealing but contradicted by topology, timing, and failure distribution evidence.
- The actual cause was a combination of no timeouts on downstream calls and eager retries, creating a feedback loop that saturated the worker pool.
- Little's Law explains how increased request time (W) exponentially raises concurrency (L), overwhelming a fixed worker pool.