4 Replies Latest reply: Mar 12, 2013 2:06 AM by Ivan Mak RSS

    Performance problems with QVW11

    ramon arcusa

      Hello to you all.


      First, I will introduce our server specs: Windows Server 2008, multi-core processor with 14 CPUs (2,53Ghz each), 24GB RAM. We moved from QV10 to QV11 one week ago (problems later mentioned appeared before upgrading).


      We have built several QlikView documents. One of them is, by far, the biggest one, weighing over 2GB of hard disk space. This one is also the most accessed document. We activated the Preload checkbox, and from that moment on, it looks like the document opens faster most of the times.


      Over the last few weeks, we have been experiencing some performance problems. Some times, QlikView "freezes" for about 10 or 15 seconds when users try to perform any action (make a selection, change the current field in a cyclical group or whatever). When things go fine, every process or calculation made by QlikView barely last less than 1 or 2 seconds, so 10 or 15 seconds is totally unacceptable.


      We have stated that, as day advances, VMCommitted and VMAllocated increase, and never decrease (Status->QVS Statistics->Performance). In Document->Performance, we configured the Document Timeout to 1 minute, so QlikView could release memory as soon as nobody is working with the document. However, it looks like it doesn't release any byte. Does QlikView ever release memory resources? It looks like it just releases memory overnight (perhaps due to the 480 minutes set as default in Document Timeout for the Server), because when we come to work early in the morning we can check that memory has been almost completely released.


      As far as I know, QV allocates memory for approximately a 10% (that could be more or less depending on many factors) of the document for each user accessing the document. When do those extra bytes of memory get released? Does it depend on the Preload checkbox? I mean, if I have the Preload checkbox activated, does that interfere with the release of the memory allocated because of every user access?


      Thank you all for your support.