Fiddler severely leaking memory

2 posts, 0 answers
  1. Nero
    Nero avatar
    1 posts
    Member since:
    May 2012

    Posted 10 Jun 2014 Link to this post

    I have noticed this for a while now. It would slowly grow and grow and grow, even if I have 100 sessions max to keep. I may have noticed a few times when it's grown past a gigabyte in memory, to start growing more exponentially, as much as two megabytes per "refresh" in browser window. However, the real problem is that it also does it when there's filters turned on. To my understanding, filters should prevent traffic that doesn't pass them from being stored anywhere. The main reason why I have noticed it, is because I work with an external API to monitor all the calls towards them (ie if the request url doesn't contain "wsapi", it doesn't get through) and I have fiddler running on the background at all times regardless of whether the API is used or not, and occasionally my system would slow down, so I would open task manager... and see fiddler hogging about 7 gigs of ram. Yes, seven gigs, almost half of my RAM, with the fiddler window being completely empty. Yes, empty. No records, none. Yet Fiddler is growing exponentially, should I forget it on for a few days without checking on its memory footprint.

    It's something that has been there for ages, and not something I think about, as I normally just restart the program (or close and start it when I need it), but since I discovered it while I had some spare time, I thought I'd make a post about it, as the internet has been rather fruitless about it, although I can see a few posts which normally relate to garbage collection... but considering I have had the slowdown with 1,5 gigs of Fiddler memory with rest of the applications pushing it far over 16 gigs (swap file to the rescue), if it really is that, the garbage collector is doing an incredibly rotten job, as the resources are definitely needed by other applications.
  2. Eric Lawrence
    Eric Lawrence avatar
    832 posts

    Posted 10 Jun 2014 Link to this post

    Hi, Nero--

    Fiddler is purely managed code, so it doesn't "leak" memory in any traditional sense. Using Task Manager is a poor mechanism for determining an application's memory consumption.

    You can force a manual garbage collection by opening Fiddler's Help > About screen.

    You can entice the .NET Framework to release idle memory to the system by explicitly minimizing the Fiddler window.

    Eric Lawrence

    Check out the Telerik Platform - the only platform that combines a rich set of UI tools with powerful cloud services to develop web, hybrid and native mobile apps.

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