Insufficient SQL database permissions for user 'Name: NT AUTHORITY\IUSR SID: S-1-5-17...

Question

Hi,
I have a customized SharePoint page that takes user input data, validate some of the data, then writes the data to a SharePoint list. If an exception occurs, it will write the error to the ULS.
All was working well in the test environments.
However, recently we noticed that in the QA environment, when it's trying to write to ULS, it causes another issue:
Insufficient SQL database permissions for user 'Name: NT AUTHORITY\IUSR SID: S-1-5-17 ImpersonationLevel: Impersonation' in database 'SP_F1_Config' on SQL Server instance 'SQL01'. Additional error information from SQL Server is included below. The EXECUTE
permission was denied on the object 'proc_putObjectTVP', database 'SP_F1_Config', schema 'dbo'.
I've traced through the code and found that it fails on the line:
    SPDiagnosticsServiceBase.GetLocal<LoggerError>();
where LoggerError is the logger class inheritng SPDiagnosticsServiceBase
I have also googled around today, but the most positive solution provided
on this page was to manually modify SQL object permission, which I believe we should not do, and would not be supported by Microsoft.
So the questions are:
Why is AUTHORITY\IUSER used for SPDiagnosticsServiceBase.GetLocal()? Should that account actually be allowed to access SharePoint databases? (This is an intranet environment and using claim based/Windows authentication, no no anonymous access would be allowed
anyway).
I've checked the Application Pool account permissions in SQL, comparing the environment that works and the one that doesn't work, and the permissions/roles/schemas look identical on server and database level. Where else can I check?
On the environment that works, I logged on as SharePoint administrator, created a new SharePoint Visual Web Part solution in Visual Studio, just to test writing to ULS. Then I press F5 in Visual Studio to debug it. It also has the same problem.
It just seems like somehow the user's identity (or whatever the identity SharePoint required) was not passed to SPDiagnosticsServiceBase.
Any suggestions, or even better, solutions would be really really much appreciated!

Answer 1

Hi，
Thanks for your sharing, it will be userful to the people who stuck with the same issue.
Best regards
Patrick Liang
TechNet Community Support