.NET application memory usage - high unused .NET and unmanaged memory and fragmentation -


i using ants memory profiler diagnose increase in memory leak facing in 1 of .net 2.0 applications. took 7 snapshots of process on period of 7.5 hours, , here tabular representation of data obtained -

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g1 reprsents generation 1 size , g2 generation 2 size. except unmanaged space , private bytes, other values in mb.

my questions -

  1. why there such high unused .net space when heap sizes low ?

  2. my large object heap goes maximum of 2 mb, , during last 3 snapshots remains @ 96 kb. why there such high large fragments, , responsible high unused space ?

  3. the unmanaged space increases constantly. responsible increase in private bytes on time ?

i @ wit's end solve issue, , have performed several analyses cant find proper solution this. ready provide other data needed.

as alex pointed out nice explanation of problem class large object heap fragmentation found here:

https://www.simple-talk.com/dotnet/.net-framework/the-dangers-of-the-large-object-heap/

the problem known in .net fx dev team , continuously been worked at. there chance symptoms fade off using more recent fx releases.

starting .net 4.5.1 there gc method call compact loh: http://blogs.msdn.com/b/mariohewardt/archive/2013/06/26/no-more-memory-fragmentation-on-the-large-object-heap.aspx however, finding root cause of lohf way more efficient wiping of heap wasting tons of ms's

let me know, if need further details how isolate such effects.

seb


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