Client Performance Slowdown

[shuffman]

Hello,

I have had a few users experiencing some really poor performance after they have been running the application for over an hour. It can take 15 seconds or more to see a character appear in a textbox after keying it. If they exit the browser and start over it behaves normally. It appears to be either a memory problem or some JavaScript that is spinning it's wheels. It doesn't appear to be any specific program doing it but i can't be sure. I don't really have a lot to go on with this. They are using Chrome and I did a performance profile with the chrome developer tools and the CTRL-F9 json dump. Any tips on how to troubleshoot this?

Thanks,

Sam

[Scott Klement]

If it gets slower over time, the most common cause of that would be a memory leak. However, this is the first time I've heard of a memory leak manifesting in Chrome. (Usually it shows up in older Internet Explorer versions -- due to bugs in that browser's implementation of JavaScript.)

You mention that it occurs in all programs -- which is consistent with a memory leak. But, then why did you send us a screen dump of a particular screen?

You mention that exiting the browser and restarting eliminates the symptoms. (Or perhaps restarts things so that it takes another hour reproduce, etc.) Does simply reloading that particular browser window/tab (without actually closing the browser) do the same thing? If so, you might consider setting up a refresh interval as described here:
http://www.profoundlogic.com/docs/displ ... h+Interval

The refresh interval causes Profound UI to, essentially, reload itself periodically. Say, for instance, things start to get slow after the screen has been redrawn 200 times... setting the refresh interval to 150 would cause it to reload itself after 150 screens, so it'll never get to 200, and therefore never slow down.

[shuffman]

Scott,

I will try the interval. I'm going set it at 25 just to be safe since i don't know how many screen writes it takes for this to occur. I will try closing just the tab next time to see if this resets everything. Are there any drawbacks to using this other than the white background while it refreshes?

Thanks

[Scott Klement]

Since it has to reload everything, the user has to wait while it downloads. If you have any sort of code that runs only when the session starts or similar, you'll probably need to rewrite it to work when it refreshes...

[shuffman]

Doing this seemed to work. It's been a couple of weeks and i haven't heard of any issues.