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PASSEDserver / sql_server_deadlock_storm
SQL Server Deadlock Storm
A poorly optimized batch job triggers a deadlock storm in SQL Server. 150+ deadlocks in 10 minutes as the batch process and OLTP transactions compete for the same table locks. Application transactions are chosen as deadlock victims, causing user-facing errors.
Pattern
DATABASE_EVENT
Severity
CRITICAL
Confidence
95%
Remediation
Remote Hands
Test Results
| Metric | Expected | Actual | Result |
|---|---|---|---|
| Pattern Recognition | DATABASE_EVENT | DATABASE_EVENT | |
| Severity Assessment | CRITICAL | CRITICAL | |
| Incident Correlation | Yes | 27 linked | |
| Cascade Escalation | N/A | No | |
| Remediation | — | Remote Hands — Corax contacts on-site support via call, email, or API |
Scenario Conditions
SQL Server 2022 Enterprise. OLTP database with 500 concurrent users. Batch import job running with SERIALIZABLE isolation. 150 deadlocks in 10 minutes. Deadlock victim: OLTP transactions. Lock escalation to table level.
Injected Error Messages (2)
SQL Server deadlock storm — 157 deadlocks in last 10 minutes, Event ID 1205: Transaction was deadlocked on lock resources, deadlock victim: SPID 87 (OLTP user query), deadlock graph showing lock escalation conflict between batch SPID 234 (SERIALIZABLE) and OLTP transactions, sys.dm_exec_requests showing 47 suspended sessions
ERP application transaction failures — SqlException: Transaction (Process ID 87) was deadlocked on lock resources and has been chosen as the deadlock victim, 35% of user transactions failing with deadlock error 1205, order processing halted, users seeing 'Your request could not be completed' errors
Neural Engine Root Cause Analysis
SQL Server is experiencing a severe deadlock storm with 157 deadlocks in 10 minutes, indicating a critical concurrency issue. The deadlock graph shows lock escalation conflicts between a batch process running in SERIALIZABLE isolation level (SPID 234) and concurrent OLTP transactions, with 47 suspended sessions suggesting resource contention. This pattern typically occurs when a long-running batch operation holds extensive locks while competing with high-frequency transactional workloads, creating a cascade of blocking and deadlocks that renders the database effectively unavailable.
Remediation Plan
1. Immediately identify and kill the problematic batch process (SPID 234) running in SERIALIZABLE isolation to break the deadlock chain. 2. Monitor active sessions and kill any remaining suspended transactions that are blocking recovery. 3. Analyze the batch process logic to implement proper transaction scoping, use lower isolation levels where appropriate, and add proper retry logic. 4. Implement deadlock monitoring alerts and consider partitioning strategies to reduce lock contention. 5. Review application connection pooling and transaction timeout settings to prevent similar cascading failures.
Tested: 2026-03-30Monitors: 2 | Incidents: 2Test ID: cmncjnlwg02yzobqet7ubdh1d