#11 diagnosing slow response in Recoll UI

None
closed
nobody
None
2017-10-14
2017-09-01
Anonymous
No

Issue

Application works successfully but there is a 10-20 second delay in displaying the list of results in the main Recoll UI window. This occurs both with the first set of results, and with subsequent pages on clicking Next.

Attempted...

Tried workaround for Result List Font from [https://www.lesbonscomptes.com/recoll/BUGS.html#b_1_13_04] but does not help.

Installation

Recoll 1.23.2 installed from PPA onto Lubuntu Artful 17.10 prereleases. Issue occurs on both LXDE and LXQT desktop flavours.
recoll package recoll_1.23.2-1build1_amd64.deb
libqt5* packages installed version 5.9.1+dfsg-5ubuntu2

Question

I am not sure that this is actually a recoll issue, but I would like advice on diagnosing where the issue arises. How can I go about analysing what is happening whilst waiting for the UI to update?

Discussion

  • medoc
    medoc
    2017-09-02

    I'm not too sure actually. You can use the command line to make sure that this is not a query speed issue. Then it would be a matter of adding traces to the code and seeing where it stops. I don't have 17.10 installed yet, so I can't even take a look.

     
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    • Artemgy
      Artemgy
      2017-09-07

      After the initial output (below), nothing appears on CLI during recoll search or display.

      ** (recoll:14295): WARNING **: Error retrieving accessibility bus address: org.freedesktop.DBus.Error.ServiceUnknown: The name org.a11y.Bus was not provided by any .service files
QApplication: invalid style override passed, ignoring it.
libpng warning: iCCP: known incorrect sRGB profile
libpng warning: iCCP: known incorrect sRGB profile
libpng warning: iCCP: known incorrect sRGB profile

      I suspect it is NOT query speed, and the Result Count Estimate appears in the status bar in a fraction of a second. It is the display of the results list that takes its time. And it it slow for each page when you 'Next'. Sometimes it is quicker if there is only one or two results.

      Also there appears to be some kind of caching, For example if I go Next through ten screens each one takes up to ten seconds to display. If I go Prev each is almost instantaneously displayed. Likewise as I go Next forward each of the ten screens of results. It is only when I press Next an eleventh time that the delay kicks back in - I assume 'something' is having to generate a new results page from scratch.

      Are there any sub-processes I could watch for CPU or memory? Any way of attaching a debugger to step through function calls? How would you, as a developer, diagnose this without resorting to traces to the code? If if you did, what are the external library calls most likely to contain the root cause? Any guidance most welcome.

       
      Last edit: Artemgy 2017-09-07
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  • medoc
    medoc
    2017-09-07

    There are no subprocesses involved in displaying result pages. I need to install ubuntu 17.10 and investigate this. As soon as I can find some time to do it.

     
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  • medoc
    medoc
    2017-09-10

    Hi,

    I installed lubuntu in a VirtualBox VM, with lxqt, and I can't reproduce the issue, things are working 'out of the box'.

    One thing you could try would be to delete the GUI preferences (~/.config/Recoll.org/recoll.conf, not to be confused with the indexing prefs in ~/.recoll), and start the GUI again to see if it changes anything. I've seen really weird problems caused by "bad stuff" in this file.

    Otherwise, I'm a bit out of ideas.

     
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  • medoc
    medoc
    2017-10-14

    Can't reproduce

     
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  • medoc
    medoc
    2017-10-14

    • status: open --> closed
    • milestone: -->
     
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