profiler shows junk duration on Virtual Server?

  • Hi There,

    We run our Development environment inside a virtual machine running Win Server 2003 64 bits with sp2

    Our SQL Server is Developer edition 64 bits, sp2

    I run a "server side" trace with a filter on the duration to keep it light but the Duration figure reported by Profiler is obviously wrong.

    It seems to be a number (65 seconds just now) very slowly increasing and completely unrelated to the actual execution time.

    Anyone seen that before?

    Any workaround?

    If not, I'll have to stop that trace because it's pretty useless...

    Thanks

    Eric

  • Are these AMD chips by any chance?

    I know there is some technology that messes with the way SQL 2005 tracks time. This is typically AMDs Quite 'n Cool technology. I've had a client having similar issues, and I believe they have applied an AMD BIOS patch. The same issue exists in SQL 2008, but I believe SQL 2008 R2 has been fixed.

    Leo

    Leo
    Nothing in life is ever so complicated that with a little work it can't be made more complicated.

  • I am not too sure how much does that mean but if I look at My Computer Properties from within the virtual machine, it says Intel Xeon...

    From within a virtual machine, is ist the real hardware or is it something emulated?

  • It's always emulated. You could theoretically take your virtual machine from one machine and install it on another one with completely different hardware and it would still work.

  • Sorry for the delay.

    I don't have direct access to the real box so I had to get someone to check for me...

    Nop, it's not an AMD, it's an Intel chip...

  • In your SQL Error log, do you have any messages that look similar to this:

    The time stamp counter of CPU on scheduler id 1 is not synchronized with other CPUs

  • Yes, I have...

    About every hour

  • It appears you have a CPU timing issue...

    I've run into this before on virtual guests. If it is a timing issue, the query stats DMV will be all over the place as well.

    You can read more about CPU timing here:

    http://support.microsoft.com/kb/931279

    I've been able to make this problem go away by setting the CPU affinity to all the CPUs in the guest (as suggested by the document), preventing SQL worker threads from jumping CPUs.

  • It must be the issue indeed.

    We are on 2005 SP2

    I have requested an upgrade to SP3

    Still wondering why we don't use 2008 by the way!

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