Payment Service HTTP 503 Spike After Release

Use this skill when payment-service starts returning HTTP 503 shortly after a release, especially after version v2.3.1.

Goal

Find whether the new release caused a database connection pool regression, then propose a safe rollback path.

Evidence to collect

1. prom_top_anomalies(service="payment-service")
   • Look for http_503_rate, p95 latency, and request volume changes.
2. loki_query(service="payment-service", query="connection pool exhausted")
   • Look for database pool exhaustion or timeout messages.
3. trace_search(service="payment-service", error_only=true)
   • Look for slow or failed spans to mysql-payment.
4. recent_deploys(service="payment-service")
   • Check whether v2.3.1 was deployed shortly before the HTTP 503 increase.
5. incident_rca_guard(...)
   • Confirm the evidence is consistent before producing the final RCA.
6. action_policy_guard(...)
   • Generate policy-checked actions.

Decision logic

A release regression is likely when all of these are true:

• payment-service has a recent deployment such as v2.3.1.
• HTTP 503 rate increases after the deployment.
• Logs include connection pool exhausted or similar DB pool messages.
• Trace evidence points to mysql-payment latency or failed spans.

Recommended action

If the above evidence is present, propose:

• rollback_canary(service="payment-service", target_revision="v2.3.0", dry_run=true) first.
• If the operator approves, call rollback_canary(..., dry_run=false, approval_id="...").
• Then call verify_recovery(service="payment-service").

Safety rules

• Never execute rollback without approval.
• Always create a checkpoint before destructive execution.
• Keep raw logs and full traces out of stable memory.
• Final answer must cite evidence IDs.

Final answer template

• Root cause: ...
• Evidence: ev_metric_http_503_rate, ev_log_pool_exhausted, ev_trace_mysql_latency, ev_deploy_v231
• Recommended action: rollback from v2.3.1 to v2.3.0 after approval.
• Verification: check HTTP 503 rate and p95 latency for 10 minutes.