Without these, a misbehaving upstream or client can cascade failures through the proxy.
- Retry: configurable policy, idempotency awareness, retry budget, retriable status codes (basic connect-retry exists but is hardcoded to 3 attempts, same backend)
- Circuit breaker: per-cluster limits, consecutive error threshold, half-open probe state
- Passive health checking / outlier detection
Note: Retry is partially implemented. Missing: configurable policy, retry budget, retriable status codes (502/503/504), per-route overrides, tried-endpoints tracking (avoid retrying same backend), body size threshold.
Without these, a misbehaving upstream or client can cascade failures through the proxy.