"John Saunders [MVP]" <john.saunders at trizetto.com> wrote in message
news:uM$CfB5OIHA.3400@T......
> I don't know if this is the best place to ask this question; if anyone has
> an idea of another place I should ask, then please let me know.
>
> At a customer site, we're seeing the virtual memory size of our COM+
> application grow until it exceeds the maximum virtual memory a process can
> have. When we look at the dumps in windbg, it looks like MSXML is the
> culprit. There is a distinctive pattern of heap usage. An attempt to
> reproduce the problem in a development environment has not (yet)
reproduced
> the out-of-virtual-memory problem, but _has_ reproduced the distinctive
> pattern of heap usage.
>
> The heap usage pattern is that several heaps consist of a few "normal"
heap
> segments, followed by a number of segments with only a single page
> committed. Each of these one-page-committed segments within a given heap
has
> twice the reserved size as the one before it, yet has only a single page
> committed. Obviously, if this keeps up, virtual memory will eventually be
> full of one-page heap segments. In fact, this is what happens at our
> customer site.
>
> We are using the normal, rental-threaded model with MSXML 4. We are using
> the DOM, with no SAX at all, and no XSL or XSD. I don't know if there's
any
> XPATH, but there can't be much of it. My test program uses many threads to
> call our COM+ application, which in turn performs MSXML calls.
>
> I've begun doing some memory allocation profiling with the AQTime 5 tool
> from Automated QA. It shows that all of the allocated segments with the
> committed vs. reserved discrepancy were allocated by a call to MSXML.
These
> calls range from CreateInstance to setAttribute. I even saw one loadXml
> call.
>
> We're in the process of narrowing this down. My test program now calls
only
> one of our COM+ methods, which performs mostly XML work. I'll be working
on
> a narrower test that only does specific MSXML calls. In the meantime, I
was
> hoping that this pattern of memory allocation is familiar to someone.
>
> Thanks for any help or suggestions,
> John
>


Can the same behaviour be reproduced in using MSXML6 ?


-- 
Anthony Jones - MVP ASP/ASP.NET