Blocking & Deadlocks

The 8 checks in the “Blocking & Deadlocks” category of a SQL Server audit: what each one verifies, its severity and the versions covered.

Checks in this category

BLK001
Active Blocking
Critical
Detects sessions currently blocked by other sessions
Versions : 2012-2025
BLK004
Deadlocks (Last 7 Days)
High
Checks the number of deadlocks that occurred in the last 7 days
Versions : 2012-2025
SESS001
Sleeping sessions with open transaction
High
Detects sleeping sessions holding an open transaction, which pin locks and prevent log truncation.
Versions : 2012-2025
BLK003
Long-Running Queries (>60s)
Medium
Detects queries running for more than 60 seconds
Versions : 2012-2025
SESS003
Oldest open transaction age
Medium
Measures the age of the oldest open transaction, which blocks log truncation and can block other sessions.
Versions : 2012-2025
BLK002
Long-Running Transactions (>5 min)
Info
Identifies transactions that have been open for more than 5 minutes
Versions : 2012-2025
BLK005
Lock Escalation Disabled Tables
Info
Identifies tables with lock escalation disabled
Versions : 2012-2025
BLK006
AG Redo/Send Queue Lag
Info
Measures the redo queue and send queue lag of AG replicas
Versions : 2012-2025