SQL Server does not exist or access denied.

[ironhide1975]

On random occasions on my website I am getting the following error message.

SQL Server does not exist or access denied.

This seems to happen randomly. The page just seems to TimeOut after a while and cause this error to occur.

If I refresh the page it seems to be fine.

 

[Sheco]

Is the database on the same physical machine as the web server?

If yes is it under a heavy load or doing a bulk operation? If no is there a lot of network traffic between the boxen?

 

[ironhide1975]

No the database is on a seperate server. Yes it is under a heavy load.

 

[Sheco]

If you could examine a log file it might be that the machine becomes unresponsive at peak load.

 

[ironhide1975]

Cool I'll check into it, many thanks.

 

[ironhide1975]

Here's some addition code samples...

Microsoft OLE DB Provider for ODBC Drivers error '80004005' 
[Microsoft][ODBC SQL Server Driver][DBNETLIB]SQL Server does not exist or access denied. 

/staff/General/masterPagesListing.asp, line 77

 

[ironhide1975]

could this be the limits of connections or ports to the server per chance?

Here's something I found online...

"
Actually another cause of:
[DBNETLIB]SQL Server does not exist or access denied.

can be a heavy loaded web server. We had an issue with this recently. The web server (Windows 2003) kept 5000 TCP sessions open to the SQL port 1433 (in time_wait state) even if only about 40 where active against the SQL Server. It didn't close them fast enough and eventually you run out of ports.

We had to inrease the max ports to 20000 and lower the TCP session termination to 30 seconds instead of the default 240 seconds to get around this."

 

[Sheco]

Oh that is interesting. So a limit of the operating system is preventing connections? Seems plausible if the load is really heavy.

If I remember correctly, when the SQL Server program execedes the connection licenses you get a more informative error message.

 

[ironhide1975]

I'm thinking this error is being caused by a network setting, throttle or server setting. I've never had this problem on any other website I've done.

 

[ironhide1975]

Okay after discussing with IT we think we found the problem, so here it is for future reference.


I found some errors in the firewall log. These errors look like IIS is attempting to authenticate to server1 using NT authentication and it should only be using SQL authentication. I checked the ODBC DSN and found a problem that may be the issue. The DSN was using “server1” as the DB server and this isn’t the best scenario for a server located in the DMZ. I’ve changed the DB server setting to use the IP address of the server1 and I’m hoping this will correct the issue. Please test and let me know.