MSSQL-REC-BLOCKING-001 · Blocking of 30 s or more during the recording

Severity	Confidence	Permission	Applies to
High	Confirmed	VIEW SERVER STATE	Recordings (codedb-lens record): SQL Server 2017+, Azure SQL MI, RDS

What it checks

The locks collector (blocking chains from sys.dm_exec_requests, every 15 s). One episode per blocking session while a blocked session waits at least 30 s (min_wait_s).

Why it matters

Sessions waited at least 30 seconds for another session to release its locks. Users see timeouts and frozen screens while it lasts.

Next action

Start with the blocker of the longest episode. A blocker in "sleeping" status with open transactions is usually an application that forgot to commit; one that is running is a long query or batch to tune or move off-peak.

How to verify

Record again during the same hours after the fix. The episodes for that blocker must be gone or much shorter.

Limitations

Samples are taken every 15 seconds, so blocking shorter than that may be missed, and an episode's length is accurate to about 15 seconds.