One of my customers has a SQL Server 2005 Standard Edition with the current service pack. Over the weekend the Windows 2003 Server had some Windows Update (all security patches) applied. Performance on batch process doing adds, deletes, and updates went from 1000 transactions to 30 transactions per second.

SQL Server is on its own server box. Web application via IIS on its own server box. Both servers are hosted in the cloud and referenced in private network (IP 192.168.x.x)

Anyone heard of any Windows Updates that bog down SQL Server 2005?

Things that we have checked:

  • Running queries across the network and directly on the SQL Server server have same performance drop, so the network infrastructure, network card, and driver do no seem to be impacting the problem.
  • Not all queries on the server are suffering the same percentage of drop, and short queries still run as fast as normal. Batch process is most affected.
  • None of the Windows Updates have any mention of SQL Server.
  • Log file is around 5 GB, database is around 4 GB

The app has been running fine for the last few months since it was implemented.

I am not convinced the Windows Update is nothing more than a coincidence timing wise, but it is hard to ignore as well.

Wondering if there were any recent battles for DBAs or developers with a Windows Update killing SQL Server performance.

  • 1
    This would be better asked on ServerFault – Paul Sasik Mar 1 '10 at 21:12

Service Pack 2 for Windows Server 2003 adds the Scalable Network Pack, which can bog down your network stack if your NIC drivers aren't fully compatible with them. Look at upgrading your NIC drivers, and if that doesn't fix it, turn off TCP Chimney via Netsh int ip set chimney DISABLED. There may be other things you need to look into here . Mind you, these only apply if Sp2 was one of the updates that was applied, and you didn't actually list the updates that you applied.

Now, you say that the network is probably not it, but I think you should look into it. It's very easy to test - disabling the chimney does require a reboot, but it's a very easy check.

  • Definitely something reasonable to check, will look into it. – Rick Schummer Mar 1 '10 at 23:15

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