[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). Full degradation of checkout for 78% of users, meeting SEV1 criteria.

deepseek-chat·prompt v1·output: en·9682ms

Root cause hypotheses

• highStripe Connect API experiencing elevated latency in us-east-1, causing downstream timeouts

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

• highNo circuit breaker on Stripe client allows all threads to block, leading to thread pool exhaustion

  Evidence: Thread pool utilization at 100% with all 200 threads blocked. Inbound queue depth 4200. No circuit breaker configured.

• mediumStripe call timeout (30s) matches inbound gateway timeout, causing cascading failures

  Evidence: p99 latency 28s hitting 30s timeout. No bulkhead isolation for Stripe calls.

Investigation checklist

1. Confirm Stripe status page for ongoing incident

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

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   Expected: Active incident for Connect endpoints in us-east-1

2. Check thread pool metrics in checkout-svc

   kubectl exec deploy/checkout-svc -- curl -s localhost:8080/metrics | grep -E 'tomcat_threads|jvm_threads'

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   Expected: tomcat_threads_busy == 200, tomcat_threads_max == 200

3. Verify downstream dependency latencies in APM

   kubectl exec deploy/checkout-svc -- curl -s localhost:8080/actuator/health | jq '.components.stripe'

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   Expected: Stripe health check failing or latency > 20s

4. Check inbound queue depth

   kubectl exec deploy/checkout-svc -- curl -s localhost:8080/metrics | grep 'http_server_requests_seconds_max'

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   Expected: Queue depth near 5000 limit

Mitigation plan

• Enable circuit breaker on Stripe client with fallback to fail-fast (return 503 immediately) to protect thread pool

  Risk: All Stripe-dependent checkouts will fail fast instead of timing out; may increase error rate but prevents thread exhaustion

  Rollback: Disable circuit breaker via feature flag or config revert

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

  Risk: Loss of Stripe payment capability; may impact revenue but prevents total checkout failure

  Rollback: Re-enable Stripe path once status page shows resolved

• Scale up checkout-svc replicas to increase thread pool capacity while Stripe is degraded

  Risk: May increase load on Stripe; temporary measure

  Rollback: Scale down to original replicas after incident

Customer impact

Approximately 78% of checkout attempts are failing with HTTP 504 errors. Users cannot complete purchases. Estimated 3000 failed checkouts in 5 minutes, with $180k GMV lost. No ETA for resolution; depends on Stripe recovery.

Postmortem draft

Follow-ups

• P0Add circuit breaker to Stripe client with fallback— service owner
• P1Implement bulkhead isolation for downstream calls— service owner
• P1Reduce Stripe timeout to 5s with retry logic— service owner
• P2Add thread pool utilization alert— on-call SRE
• P2Review all downstream dependency configurations for circuit breakers— platform team