Copied to clipboard

Flag this post as spam?

This post will be reported to the moderators as potential spam to be looked at

  • Steve Smith 75 posts 158 karma points
    Aug 10, 2020 @ 08:28
    Steve Smith

    Help diagnosing memory leak

    Hi all,

    I've posted here before about our Umbraco memory leak - which has been a battle we've been fighting with our solution for some time. Briefly - every 3 or 4 days, our site exhausts the 7/8Gb available to it's Azure App Service, causing some down-time whilst recovering (usually it restarts within 5 minutes, but other times ... it doesn't).

    We're on 7.15.5 - which was recommended to us due to there being a fix to the caching dependency, which had a slow memory leak. However, it didn't solve the problem for us unfortunately.

    I've started taking memory dumps over the lifetime of a single app run/cycle. One issue seems to be that the total size of the analysed part of memory dump, is nowhere near the amount of memory actually being consumed. I assume therefore that the leaking memory is "unmanaged".

    Looking for duplicate strings in the dump, I did find one curious thing - and I wonder if I could run it past the experts here?

    As the life of the app cycle progresses, we have more and more "string" reference duplicates to one of our projects/assemblies appearing in memory. That is, a string like this:

    [our.project], Version=, Culture=neutral, PublicKeyToken=null

    (where [our.project] is the name of a project/assembly from our solution)

    When memory is still around 1Gb, this appears maybe 25,000 times in the dump. As memory usage increases, so do the number of duplicate string entries. In a later dump, it appears more than 78,000 times.

    My hunch is that this is providing a clue to the assembly/project that is causing our memory leak - but I wondered if anyone had seen strange behaviour like this before, and had any hints for us?



Please Sign in or register to post replies

Write your reply to: