🔒 Paid
Deadlock Storm
Checkout routes through Order Service, and both Order Service and Inventory Service write to the same PostgreSQL database. Since a recent deployment, concurrent checkouts have started deadlocking in the database — transaction retries, lock wait time, and checkout failures are all climbing. Order correctness and inventory accuracy both depend on these writes landing cleanly, so neither service's write path can simply be taken offline. Diagnose why the two services are colliding on the same locked rows and restore reliable checkout throughput without just burying the conflict under more retries.
- Difficulty
- Senior
- Expected Time
- ~16 min
- Category
- Databases & Storage
Skills
- Diagnosing lock-order deadlocks across services sharing a database
- Distinguishing masking a deadlock from removing its root cause
- Recognizing when more retries or concurrency amplify contention
- Evaluating a safe-but-slow emergency mitigation against a durable fix
System Architecture
- Checkout
- Order Service
- PostgreSQL
- Inventory Service
This is a Pro scenario. Upgrade to Pro to unlock it.
Upgrade to ProBack to Incidents