[Eval][v3][en] Third-party payment gateway timeouts cascade into checkout outage

Summary

Severity reasoning: User-facing outage: checkout success rate dropped to 22% (below 99% threshold), error rate >1% for >5 minutes, revenue path broken (estimated $180k GMV lost). This meets SEV1 criteria.

deepseek-chat·prompt v3·output: en·12353ms·2002↑ / 2026↓ tok·$0.00277

Root cause hypotheses

• highStripe Connect API latency spike caused thread pool exhaustion in checkout-svc

  Evidence: APM shows Stripe Connect API p99 latency jumped from 800ms to 27s. Thread pool utilization at 100%, all 200 threads blocked. Stripe status page confirms elevated latency for Connect endpoints in us-east-1.

• highNo circuit breaker on Stripe client allowed unbounded retries or waiting

  Evidence: Configuration review shows no circuit breaker or bulkhead for Stripe calls. Inbound queue depth 4200 (limit 5000) indicates requests piling up.

• mediumStripe timeout (30s) matches inbound gateway timeout, causing no early failure

  Evidence: Stripe call timeout is 30s, same as inbound gateway timeout. This means downstream calls can block threads for the full timeout period without fast-failing.

• mediumStripe issue is isolated to us-east-1, but checkout-svc only calls that region

  Evidence: Stripe status page mentions us-east-1. No evidence of multi-region Stripe configuration.

• lowAuth-svc or fraud-svc also affected but not detected

  Evidence: APM shows auth-svc and fraud-svc latencies normal. No evidence of impact.

Investigation checklist

1. Verify Stripe status page for current incident details

   curl -s https://status.stripe.com/api/v1/incidents | jq '.incidents[] | select(.status != "resolved")'

   Copy

   Expected: Incident with elevated latency for Connect endpoints in us-east-1, status 'investigating' or 'identified'

2. Check thread pool utilization and queue depth in checkout-svc

   kubectl exec -n prod deploy/checkout-svc -- curl -s localhost:8080/actuator/threadpool | jq '.threadPool.utilization, .queueDepth'

   Copy

   Expected: utilization: 100%, queueDepth: near 5000

3. Check Stripe client configuration for circuit breaker and timeout

   kubectl exec -n prod deploy/checkout-svc -- cat /app/config/stripe.yml | grep -E 'timeout|circuit|bulkhead'

   Copy

   Expected: timeout: 30000, no circuit breaker or bulkhead settings

4. Check APM for Stripe Connect latency trend

   curl -s 'http://apm-dashboard:8080/api/v1/metrics?service=checkout-svc&metric=stripe.latency&time=18:35-18:45' | jq '.series[] | select(.tags.endpoint=="/v1/payment_intents")'

   Copy

   Expected: p99 latency spiking from 800ms to 27s starting at 18:35

5. Check if Stripe has a failover region or alternate endpoint

   kubectl exec -n prod deploy/checkout-svc -- cat /app/config/stripe.yml | grep -E 'region|endpoint'

   Copy

   Expected: Only us-east-1 endpoint configured

Mitigation plan

• Enable circuit breaker on Stripe client to fail fast when latency exceeds threshold (e.g., 5s)

  Risk: May cause false positives if threshold too low; could temporarily block legitimate traffic if Stripe recovers quickly

  Rollback: Disable circuit breaker by reverting config change

• Reduce Stripe call timeout from 30s to 5s to free threads faster

  Risk: Some legitimate Stripe calls may timeout if latency is high but not failing; could increase error rate

  Rollback: Revert timeout to 30s

• Implement bulkhead isolation for Stripe calls (dedicated thread pool of 50 threads)

  Risk: May limit throughput to Stripe; if bulkhead pool is too small, Stripe calls may queue up

  Rollback: Remove bulkhead config or increase pool size

• If Stripe incident persists, disable Stripe payment path and fall back to alternative payment provider or show maintenance page

  Risk: Lost revenue from Stripe payments; customer frustration if payment fails

  Rollback: Re-enable Stripe path after incident resolved

Customer impact

Approximately 78% of checkout attempts are failing with a 504 error. Customers cannot complete purchases using credit/debit cards processed through Stripe. Estimated 3000 failed checkouts in the last 5 minutes, with $180k in lost revenue. No ETA for resolution; Stripe is investigating.

Postmortem draft

Follow-ups

• P0Add circuit breaker to Stripe client with appropriate thresholds— checkout-svc team
• P0Implement bulkhead isolation for Stripe calls (dedicated thread pool)— checkout-svc team
• P1Reduce Stripe call timeout from 30s to 5s— checkout-svc team
• P1Add monitoring alerts for thread pool utilization and queue depth— platform team
• P1Review all external dependency configurations for resilience patterns (circuit breaker, bulkhead, timeouts)— platform team
• P2Create runbook for Stripe dependency failure with mitigation steps— on-call SRE
• P2Evaluate multi-region Stripe configuration for failover— checkout-svc team