Dllhost.exe Memory Leak Problem - IIS 5

External Since: Nov 28, 2003 Posts: 1

I have seen a lot of discussion on this forum about this problem. We are experiencing this on an Intranet server where memory footprint of one our dllhost.exe processes gradually expands until it either runs out of memory or is unloaded.
Two points that we wish to make in connection with this problem:

1) We found that the use of IISState 3.2 wasn't very useful in debugging this problem for ASP/COM+ applications. As well it pauses the process of interest while ouputting a thread dump. It only gives CPU times, etc. can you infer any memory-based information from the output? (Or are we being dumb:)

2) Has anyone had any experience of the WinHTTP 5.1 component being called from an ASP page causing a memory "creep" problem with a dllhost.exe process? Or with the application object if it is used to carry around HTTP data grabbed from text retrieved from a WinHTTP instance. At the moment I just have a hunch that this is the application fault causing the problem. WinHTTP is used for caching in-page tabbing on a page listing various document links.

Many thanks in advance.

Gavin

External Since: Aug 24, 2003 Posts: 1478

1) IISState isn't memory aware, so you are absolutely right.

2) I haven't seen that, but then again I don't see everything. I would
recommend starting w/installing the latest MDAC (2. Cool

since 2.7 (previous to
SP1) and earlier had a leak. Also, my experience is that memory leaks are
wicked hard to track down. As a general rule I do the following:

1) Install latest bits (Win OS Service Packs, MDAC, script engines
(msdn.microsoft.com/scripting), and XML). Doesn't always help, but that
code is hit a lot and I would hate to spend hours tracking down a problem
already fixed.
2) If you have any custom COM objects, put them in their own COM+ server
package and see if the leak follows them. There will be a perf hit for
this, but except for some specific scenarios, your users won't notice. If
the leak does follow, then you can check w/the author/vendor of the DLL to
see if there is a newer (fixed) version.

If those 2 suggestions don't help, then I would recommend opening a case
w/MS Support.

Pat

"Gavin" <gavin.mclellan RemoveThis @strathclyde.pnn.police.uk> wrote in message
news:F75E05D3-6FD4-46DB-B664-09EABF99F574@microsoft.com...
> I have seen a lot of discussion on this forum about this problem. We are
experiencing this on an Intranet server where memory footprint of one our
dllhost.exe processes gradually expands until it either runs out of memory
or is unloaded.
> Two points that we wish to make in connection with this problem:
>
> 1) We found that the use of IISState 3.2 wasn't very useful in debugging
this problem for ASP/COM+ applications. As well it pauses the process of
interest while ouputting a thread dump. It only gives CPU times, etc. can
you infer any memory-based information from the output? (Or are we being
dumb:)
>
> 2) Has anyone had any experience of the WinHTTP 5.1 component being called
from an ASP page causing a memory "creep" problem with a dllhost.exe
process? Or with the application object if it is used to carry around HTTP
data grabbed from text retrieved from a WinHTTP instance. At the moment I
just have a hunch that this is the application fault causing the problem.
WinHTTP is used for caching in-page tabbing on a page listing various
document links.
>
> Many thanks in advance.
>
> Gavin
>