A ratio against the healthy phase cannot bound either metric. Once the Redis
circuit breaker opens, a request skips Redis instead of waiting on its socket
timeout, so the chaos phase can measure cheaper than the baseline it is compared
against: local runs came in at 0.61x baseline p90 while a log-bytes ratio read
724x. Splitting Budget into RatioBudget and AbsoluteBudget lets RSS and CPU keep
the ratio they need, since both are machine-shaped, while latency and log volume
get the wall-clock ceiling a user actually cares about.
Co-Authored-By: Claude Code <noreply@anthropic.com>
CLIENT PAUSE ALL for the length of the chaos phase instead of CLIENT PAUSE WRITE, so every Redis touchpoint on the request path times out rather than just the writes. The pause is sized to the phase because it freezes the control connection too; teardown's CLIENT UNPAUSE is a safety net for a phase that overran
Latency, RSS and CPU are now budgeted as chaos-over-baseline ratios (p50/p90/p99 for latency and RSS, CPU seconds per request once) through a small phase_budget module, replacing the machine-shaped absolutes. The Redis timeout rate is reported but no longer asserted
The final /metrics scrape waits for litellm_deployment_failure_responses_total to stop moving, since that counter is bumped from the async logging queue and lagged the load generator by thousands of increments. The model group carries a unique marker so a deployment left behind by an aborted run cannot absorb this run's retries
Co-Authored-By: Claude Code <noreply@anthropic.com>
