EXCEPTION_ACCESS_VIOLATION during CHECKDB

gerhau

Hi
We have version 5.0.11, and each week when we are running CHECKDB on DBs, we very often get an error of the type c0000005 EXCEPTION_ACCESS_VIOLATION and it is always a process/spid running one of the SQL Monitor queries that has been the reason and gets terminated. Anyone else having this problem?

Alex B

Hi Gert,

What version of SQL Server are you using? We have had some customers get this issue and one of them was able to get a response from Microsoft:

Basically SQL Server worker stores the last wait information string into a string and the wait string is copied further. There are wait types like OLEDB_WAIT, that directly stores the wait string pointer to this field instead of copying the wait string. The DMV for waiting tasks goes over this field and retrieves the wait string either by copying the wait string directly or by dereferencing it depending upon the wait type. There is a synchronization issue between setting the wait type and the wait string which is why the presumed ACCESS_VIOLATION while we retrieve the wait string. This shows up all the more with monitoring softwares as they would heavily use the DMVs.

This instance was with SQL Server 2014 and they recommended to upgrade to SP1 CU1 which is where the fix was ported in PCU1 branch.

The fix build for PCU1 branch was 12.0.4416 which is why the above recommendation.

Public KB:
3067828 FIX: Access violation occurs when you connect to an instance of SQL Server 2014

http://support.microsoft.com/kb/3067828/EN-US

I hope that helps, let me know if you have a different version of SQL Server and perhaps we can find a KB for that version related to this issue!

Kind regards,
Alex

gerhau

Hi Alex and thx for Your reply.

We are running different Versions of SQL Server, but I think you are right that the error has come on SQL SErver 2014-instances. I can see that we have not the CU where the issue was resolved.
We will try the CU.
Thank you.

Alex B

Hi Gert,

Ah righto, hopefully that does it for you. Please let us know how it goes!

Kind regards,
Alex