[Eval][v1][en] Third-party payment gateway timeouts cascade into checkout outage

Summary

Severity reasoning: User-facing outage with revenue impact (estimated $180k GMV lost), affecting ~78% of checkout attempts. Full outage of a critical payment path.

deepseek-chat·prompt v1·output: en·9142ms·1370↑ / 1439↓ tok·$0.00195

Root cause hypotheses

• highStripe Connect API latency spike in us-east-1 causing downstream timeout

  Evidence: APM shows Stripe /v1/payment_intents p99 jumped from 800ms to 27s; Stripe status page confirms elevated latency for Connect endpoints in us-east-1 since 18:35 UTC.

• highNo circuit breaker on Stripe client causing cascading thread pool exhaustion

  Evidence: Thread pool utilization at 100% with all 200 worker threads blocked; Stripe call timeout matches inbound timeout (30s), no bulkhead isolation.

• mediumInbound request surge amplifying Stripe latency impact

  Evidence: Inbound queue depth 4200 (limit 5000), indicating high traffic volume; combined with slow Stripe responses, threads are held longer.

Investigation checklist

1. Confirm Stripe latency via APM

   curl -s 'http://apm-dashboard:8080/api/traces?service=checkout-svc&span=stripe-payment&from=18:35&to=18:45' | jq '.p99_latency_ms'

   Copy

   Expected: Value near 27000ms, confirming Stripe is the bottleneck.

2. Check thread pool state

   kubectl exec deploy/checkout-svc -- curl -s localhost:8080/actuator/threaddump | grep 'pool-1-thread' | wc -l

   Copy

   Expected: 200 threads in BLOCKED or WAITING state.

3. Verify Stripe status page

   curl -s 'https://status.stripe.com/api/v1/incidents?since=18:30' | jq '.incidents[] | select(.name | contains("Connect"))'

   Copy

   Expected: Incident with status 'investigating' for Connect endpoints in us-east-1.

4. Check if circuit breaker exists

   kubectl exec deploy/checkout-svc -- grep -r 'circuitBreaker' /app/config/

   Copy

   Expected: No output, confirming no circuit breaker configured.

Mitigation plan

• Enable feature flag to disable Stripe payment path and fall back to a degraded mode (e.g., show 'payment unavailable' or use alternative provider if available).

  Risk: Customers cannot complete checkout via Stripe; potential revenue loss but prevents further timeouts and thread exhaustion.

  Rollback: Disable the feature flag to re-enable Stripe path once Stripe recovers.

• If fallback not possible, increase thread pool size temporarily to 400 and reduce Stripe timeout to 10s to fail fast.

  Risk: Increased thread count may cause memory pressure; shorter timeout may cause partial failures but reduces thread blocking.

  Rollback: Revert thread pool to 200 and timeout to 30s after incident.

Customer impact

Approximately 78% of checkout attempts are failing with HTTP 504 errors. Users see a timeout or error page after 30 seconds. Estimated 3000 failed checkouts in 5 minutes, with $180k GMV lost. No ETA for resolution; dependent on Stripe recovery.

Postmortem draft

Follow-ups

• P0Add circuit breaker to Stripe client with fallback logic— service owner
• P1Implement bulkhead pattern for downstream calls (separate thread pool for Stripe)— service owner
• P1Reduce Stripe timeout to 10s and add retry with exponential backoff— service owner
• P2Add alert on thread pool utilization >80% and queue depth >3000— on-call SRE
• P2Review and update incident response runbook for Stripe dependency failures— platform team