Critical: SQL Server 2019 CU32 Crash – c0000005 Access Violation (sqldk.dll) – Production Impact

Question

Dear Microsoft Support Team,We are experiencing repeated unexpected shutdowns of our production SQL Server instance and would like to raise a critical support ticket for investigation.Environment Details:

• Product: Microsoft SQL Server 2019 Enterprise (Core-based Licensing)
• Version: 15.0.4430.1 (RTM-CU32)
• KB: KB5054833
• OS: Windows Server 2019 Standard Evaluation (Build 17763)
• Platform: Virtual Machine (Hypervisor)
• Edition: Enterprise (64-bit)
• Licensing: Fully licensed (paid)

Issue Description:The SQL Server service terminates unexpectedly with the following fatal error:

• Exception Code = c0000005 (EXCEPTION_ACCESS_VIOLATION)
• Faulting module: sqldk.dll

The crash generates stack dumps (SQLDump files), and the service stops abruptly, causing production disruption.Based on the dump analysis, the exception occurs within core engine components (sqldk.dll), potentially during task/scheduler execution. The issue appears to be triggered while executing a stored procedure in one of our production databases.We have observed the following:

• Repeated access violation exceptions (c0000005)
• SQLDump files generated
• Service termination without graceful shutdown
• No standard “out of memory” (701/802) errors prior to crash
• Prior log entries showing intermittent page-related I/O warnings

Business Impact:This is a production system, and the unexpected shutdown results in application downtime and operational impact.Actions Already Taken:

• Reviewed SQL ERRORLOG and stack dumps
• Verified SQL Server build (CU32)
• Initiated DBCC CHECKDB on affected database
• Reviewing storage and VM health
• Confirmed sufficient physical memory (102 GB RAM)

Request:We request Microsoft to:

• Analyze the generated dump files
• Confirm whether this is a known issue in SQL Server 2019 CU32 learn.microsoft.com +2
• Provide recommended hotfix / GDR / configuration changes
• Advise on mitigation steps to prevent further service crashes

Please treat this as a high-priority production issue.Kindly advise on next steps and secure upload instructions for dump files.Thank you.Dear Microsoft Support Team,

We are experiencing repeated unexpected shutdowns of our production SQL Server instance and would like to raise a critical support ticket for investigation.Environment Details:

• Product: Microsoft SQL Server 2019 Enterprise (Core-based Licensing)
• Version: 15.0.4430.1 (RTM-CU32)
• KB: KB5054833
• OS: Windows Server 2019 Standard Evaluation (Build 17763)
• Platform: Virtual Machine (Hypervisor)
• Edition: Enterprise (64-bit)
• Licensing: Fully licensed (paid)

**Issue Description:**The SQL Server service terminates unexpectedly with the following fatal error:

• Exception Code = c0000005 (EXCEPTION_ACCESS_VIOLATION)
• Faulting module: sqldk.dll

The crash generates stack dumps (SQLDump files), and the service stops abruptly, causing production disruption.Based on the dump analysis, the exception occurs within core engine components (sqldk.dll), potentially during task/scheduler execution. The issue appears to be triggered while executing a stored procedure in one of our production databases.We have observed the following:

• Repeated access violation exceptions (c0000005)
• SQLDump files generated
• Service termination without graceful shutdown
• No standard “out of memory” (701/802) errors prior to crash
• Prior log entries showing intermittent page-related I/O warnings

**Business Impact:**This is a production system, and the unexpected shutdown results in application downtime and operational impact.Actions Already Taken:

• Reviewed SQL ERRORLOG and stack dumps
• Verified SQL Server build (CU32)
• Initiated DBCC CHECKDB on affected database
• Reviewing storage and VM health
• Confirmed sufficient physical memory (102 GB RAM)

**Request:**We request Microsoft to:

• Analyze the generated dump files
• Confirm whether this is a known issue in SQL Server 2019 CU32
• Provide recommended hotfix / GDR / configuration changes
• Advise on mitigation steps to prevent further service crashes

Please treat this as a high-priority production issue.Kindly advise on next steps and secure upload instructions for dump files.Thank you.

Answer 1

The issue you are experiencing with SQL Server 2019 CU32, specifically the repeated unexpected shutdowns and access violation errors (c0000005) related to the sqldk.dll module, is indeed concerning. Based on the context provided, this could be linked to known issues in SQL Server 2019, particularly with the SESSION_CONTEXT function and its interaction with parallel execution threads, which may lead to incorrect results or access violations in certain scenarios.

Here are some steps and recommendations that may help address this issue:

1. Analyze Dump Files: It is crucial to analyze the generated SQLDump files to identify the root cause of the access violation. This analysis can provide insights into whether the issue is a known bug or if it requires further investigation.
2. Known Issues: Review the known issues related to SQL Server 2019 CU32. As of the latest updates, there may be specific bugs that have been documented, and Microsoft may have released hotfixes or workarounds for these issues.
3. Hotfixes and Configuration Changes: Check for any available hotfixes or General Distribution Releases (GDR) that address the access violation issue. Sometimes, applying the latest cumulative updates or patches can resolve underlying problems.
4. Mitigation Steps: To prevent further service crashes, consider the following:
   • Ensure that your SQL Server instance is updated to the latest cumulative update.
   • Review and optimize the stored procedures that are causing the crashes, particularly if they involve complex queries or parallel processing.
   • Monitor the system for any performance issues that may correlate with the crashes, such as high CPU usage or memory pressure.
5. Contact Microsoft Support: Since this is a production issue, it is advisable to contact Microsoft Support directly for assistance. They can provide specific guidance based on the dump analysis and your environment details.

Please ensure that you have collected all relevant logs and dump files before reaching out to support, as this will facilitate a quicker resolution.

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References:

• KB5054833 - Cumulative Update 32 for SQL Server 2019

Answer 2

It sounds like you are trying to open a support case. This is not the place to do that, but you open that through the support channel you have in your support contract.

Beware that SQL 2019 are out of mainstream support, so while Microsoft may help you with analysing the stack dump, you cannot expect a fix.

You say this:

Prior log entries showing intermittent page-related I/O warnings

This sounds serious. Can you share some examples of these warnings?