Symptoms
Assume that you have a script that uses event notifications for AUDIT_LOGIN and AUDIT_LOGIN_FAILED events in Microsoft SQL Server 2016 and 2017. When you run the script, you will notice that the TempDB grows rapidly in size.
You can use the below query to check if space allocated to TempDB internal objects is correctly deallocated.
SELECT *
FROM (
SELECT TS.internal_objects_alloc_page_count , TS.internal_objects_dealloc_page_count, [Net Allocation MB] = CAST((TS.internal_objects_alloc_page_count - TS.internal_objects_dealloc_page_count) AS DECIMAL(15, 2)) / 128
, TS.session_id
, ER.command
FROM sys.dm_db_task_space_usage TS
INNER JOIN sys.dm_exec_requests ER ON ER.request_id = TS.request_id AND ER.session_id = TS.session_id
where TS.session_id < 50
) internal
where [Net Allocation MB] != 0
Cause
This issue occurs because of a regression in Cumulative Update 6 for SQL Server 2016 Service Pack 1.
Resolution
This issue is fixed in the following cumulative updates for SQL Server:
Cumulative Update 10 for SQL Server 2017
Each new cumulative update for SQL Server contains all the hotfixes and all the security fixes that were included with the previous cumulative update. Check out the latest cumulative updates for SQL Server:
Status
Microsoft has confirmed that this is a problem in the Microsoft products that are listed in the "Applies to" section.
References
Learn about the terminologythat Microsoft uses to describe software updates.
