One thing we have just noticed is that the Dllhost.exe which is hosting our
com+ dll's is page faulting extrememly excessively
( average of 700 page faults per sec when procesor object charted in
perfmon) in Com+ .
In Nt 4.0/Mts it is no where near this figure.
Any ideas what could be causing this?
Our threading model is "Both" for all our objects.

Charles Gamble.

-----Original Message-----
From: Richard Blewett [mailto:richard.blewettVIRGIN.NET]
Sent: 03 October 2001 16:06
To: DCOMDISCUSS.MICROSOFT.COM
Subject: Re: COM+ and Performance

Sorry, I didn't mean the COM+ subsystem, I mean't that the OS in general -
disk I/O etc was faster in Win2K than NT. There are loads of factors which
can affect your performance when running under COM+ and straight porting
from MTS to COM+ isn't necessarily an optimal way to go. The context
architecture and threading issues are much more complex under COM+ (theres
alot more choice for starters).

Richard
http://staff.develop.com/richardb

-----Original Message-----
From: Distributed COM-Based Code [mailto:DCOMDISCUSS.MICROSOFT.COM]On
Behalf Of Christine Wolak
Sent: 03 October 2001 15:36
To: DCOMDISCUSS.MICROSOFT.COM
Subject: COM+ and Performance

We too have been having performance problems with our application on
Windows 2000. Here's a summary of where we are now, in case it helps
anyone:

Our application was taking about 2.3 times as long under Win2k as compared
to NT. We got a hotfix from Microsoft which got us about 0.6 of that 2.5
back. This hotfix was supposed to provide MTS emulation mode (as far as
max apts per thread, or max threads, or something like that), but the
emulation mode itself didn't make any difference in our application - just
having the hotfix did.

Then, all of a sudden we got all but 0.1 of it back. A significant
improvement! The traces we did pointed to the function
GetQueuedCompletionStatus, which seemed to have to do with I/O in some
way. I think I think this improvement came because of
manually/specifically stopping and restarting DTC (rebooting the machine
did NOT do the trick). Microsoft never did say for sure why or whether
stopping DTC fixed this, what might have caused it to take up so much time
all of a sudden, how to keep it from happening, etc. We haven't seen the
problem crop up again, but if we do, Microsoft says that they'll want to do
some poking around at call stacks and stuff.

Another thing that did not apply to us but may apply to others was a memory
allocation issue that was broken in SP1 but fixed in SP2.

We also did some testing to force everything into ONE BIG CONTEXT, and that
had no real impact on our performance. We have one big
package/application, though, so maybe that has something to do with it.

I must respectfully disagree with Richard Blewett, who said "for a properly
configured server, Win2k is simply faster than NT". This is NOT the case
for every COM application, and as far as I could tell from Microsoft,
there's not much in the way of "configuration" of your server that you can
do to speed up performance, anyway. Maybe for WELL-DESIGNED systems, or
small systems (we have 71 DLLs in COM+), or some other scenario.
But "configuration of the server" didn't seem to have anything to do with
it.

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