ISAPI on IIS5 - memory usage

IIS5, server is also running out COM+ business objects.

Start with a clean booted server.
Start the IIS service in the morning and you can see the memory usage
creeping up as the server gets busier. It eventually levels out and runs
stable with lightly varying memory usage throughout the day.

At night we see the COM+ business objects deactivate as useage stops and
this obviously frees up memory, but when all users have stopped using the
service we are still 40meg down on the amount of free memory there was in
the morning before IIS started.

Does this seem right for a moderately heavy used IIS server ?

We are using Perfmon to gather the stats on the server as this is a live
customer environment and unfortunately we cannot install any additional
non-MS profiling tools on the server.

Martin

David
Tue Aug 03 22:33:03 CDT 2004

What you describe seems perfectly reasonable to me.

Basically, for any workload, you should expect the following:
1. "initial state" -- this is when IIS first starts and hasn't done anything
2. "idle state" -- this is when IIS has served some requests, but hasn't
done anything in a long time
3. "steady state" -- this is when IIS is executing your workload perfectly

"initial state" is NOT "idle state" (so it is perfectly fine to find "idle
state" to be 40MB down in memory from "initial state" -- for example, IIS
may be caching some expensive calculations done since "initial state" and it
wants to keep it for future "steady state"). Meanwhile, "steady state"
should remain stable over the long-run.

If you find "idle state" to be constantly depleting more and more memory, or
if "steady state" keeps increase more and more memory usage, then you should
be concerned.

Thus, I would be concerned only if you see the following when you do not
restart IIS, do not change the workload, nor change the general user
traffic:
-- repeat day 2 and find yourself 80 meg down, day 3 120 meg down, etc --
and it doesn't seem to stop going down lower
-- repeat day 2 and it takes more memory before leveling out (or never
levels out), and day 3 gets worse, etc.

--
//David
IIS
This posting is provided "AS IS" with no warranties, and confers no rights.
//
"Martin" <Martin.stephenson__@__Savant.co.uk> wrote in message
news:OCvGlTGeEHA.2764@TK2MSFTNGP11.phx.gbl...
IIS5, server is also running out COM+ business objects.

Start with a clean booted server.
Start the IIS service in the morning and you can see the memory usage
creeping up as the server gets busier. It eventually levels out and runs
stable with lightly varying memory usage throughout the day.

At night we see the COM+ business objects deactivate as useage stops and
this obviously frees up memory, but when all users have stopped using the
service we are still 40meg down on the amount of free memory there was in
the morning before IIS started.

Does this seem right for a moderately heavy used IIS server ?

We are using Perfmon to gather the stats on the server as this is a live
customer environment and unfortunately we cannot install any additional
non-MS profiling tools on the server.

Martin