3 Replies Latest reply: Jun 26, 2010 8:27 AM by Stefan Bäckstrand RSS

    High Page Faults per Second

    Brent Nichol

      Using performance monitor on the server containing qlikview Server, I'm seeing spikes in the Page Faults per second. The system is averaging 1500 with small spikes of 6000 - 10000, but when the number spikes to 60,000, RAM in use jumps to 100%. I presume this are linked, but I'm not sure if one is causing the other.

      Are these values normal?

      Is there anything I can do to combat this situation?

      Pertinent Info: Windows Server 2008, Dual core 3GHz Xeon processor, 34 GB RAM, QVS v9 SR4

      Any suggestions would be appreciated,

      B

        • High Page Faults per Second

          Optimize qv apps or buy additional ram, regards

          • High Page Faults per Second
            Stefan Bäckstrand

            The Page Fault count should be watched at with carefulness. All systems have (Soft) Page Faults, which is basically when referenced memory pages have been moved from one place in memory to another, whereas Hard Page Faults are when referenced memory pages have been moved from physical memory to virtual (swapped to page file) - those are the ones that will cause real performance problems.

            Looking at the Page Faults on it's own is quite useless, and misleading, since it's value include both Soft and Hard Page Faults. To set the apart, you will have to look at the Page Inputs/sec meter, which measures the rate at which pages are read from disk (page file) to resolve Hard Page Faults.

            Anyways, I wouldn't be surprised if a QVS system have a somewhat high count of (Soft) Page Faults - but it's not always a problem. What you need to be aware of is the hard ones, and especially if your memory usage are nearing the QVS Working set limit values (default 70/90%) - that is, when available physical memory is low.

            It might be that Windows Server 2008 have other names for these counters (I can't remember them right now), but what you need is probably always under the Memory performance object.