You have a nice day, but something is missing. Your first debug tryout, after some hours of refactoring and new feature coding. After the successful built, you get your first exception (the usual handled exception that is logging something). Usually the exception is self-explained, it gives you the right information and with a little bit of help from the call stack you pin-point the failure. So, let’s see the code…xmmmm…the error is somewhere on my tested-and-working-perfect-until-now part of my module… The exception is accompanied with a transaction lock. But why? You keep unlocking the database via the Activity Monitor of SQL Management Studio, you retest the code, step by step, but you can’t pinpoint the the problem. Why my thread does that to me, what have I done? Why does it lock my data during the business object save?
As a matter of fact, during the day, I have done 3 things in general:
- I have been coding in a region, not even executed when the lockout occurs.
- I have participated in updating the db server (another physical machine)
- I have deployed several updates to my system, including SP3, during the previous night.
So after an hour of pair-debugging, my colleague concludes that there isn’t anything wrong with the code itself, so the first bullet is gone. The problem occurs when data switches transaction mode during persistence, to distributed transaction, so we have two machines, with “maybe” recently-damaged MSDTC settings. Either my machine or the db server. By restarting after checking the settings at the db server, the problem still exists. So, the 2nd bullet is gone too. What is wrong with my pc after all?
And then, after a couple of hours I hear a magic voice screaming to me: OMG!!! Check Immediately your firewall! And there it was, the filthy, stupid (not even a) bug… that had jumped from the code and settled somewhere else. The newly-during-the-night-updated system, had restored settings and rules at firewall, ending the communication of my Microsoft Distributed Transaction Coordinator with the outer world…
Tragic….but still funny :P
