Tech Trained Monkey

Everyday Problem Solvers

Category Archives: Database

Advanced Troubleshooting Sql Server Pt.1

Detecting a Bad SPN

Okay, we all know the error that this causes. Even saying SSPI context is bad juju, and I feel dirty when I talk about it, but it has to be said:

Cannot generate SSPI Context

This is a generic error that can be caused by 1000 different things, but experience has shown me that 98% of the time, it is caused by 1 of 2 problems. Either the server is not able to connect to a domain controller to establish the SSPI context or there is an invalid SPN for the SQL Server service in AD. To verify if the domain controller connection may be a problem, I check the System event log. There may be errors stating that SQL Server was not able to connect to a domain controller or kerberos errors. The error logged may have occurred several days before you see the SSPI context errors. 99% of the time, this error is resolved by rebooting the server.

I want to talk about the second cause. An invalid SPN will cause this error. No SPN at all will NOT cause this error. That bears repeating: No SPN at all will NOT cause this error. Adding an SPN to AD will NOT fix this error. Setting up kerberos or constrained delegation when there is an invalid SPN will NOT fix this error. Starting to see a pattern? Read more of this post


Why integers are lousy primary keys

When I was a noob (about 2 years ago) I took a freelance gig to develop a simple system for a small shop. Very basic stuff. Few weeks ago the owner called me saying that he was very happy but he was facing a problem… You see, his business grew and he now has 3 shops, all of them using my system, and he wants to consolidate on one database. Well, as you can imagine I only managed to accomplish this by replacing the primary keys. They were all integers, now they’re GUIDs. The reason? Integers clash very easily!  Read more of this post