Is this a memory leak?

[ianstirkcv]

Hello,

I wonder if you can please help…

We are running a web application built using .net framework version
1.0, service pack 2, running on Windows 2000 server, service pack 3.
The server has 1 gigabytes of RAM.

We are using Perfmon to monitor memory usage of aspnet_wp.exe, CPU
usage, and % time in the Garbage Collector.

We run a test that involves processing 3 pages in a web application
(these do some database access, remoting to a business object layer,
and displaying some results). Astra LoadTest is used to simulate 15
concurrent users, using the application for about 5 hours.

The memoryLimit value in the Machine.config file has been set to
"9999". This is because when it was set to 60% the aspnet_wp.exe
recycled, resulting in lost of data.

The PerfMon results show memory usage as follows:

Start: 80M
After 1 hour: 300M
After 2 hours: 560M
After 3 hours: 680M
After 4 hours: 820M
After 5 hours: 820M

The results show that an increasing amount of memory is being used,
until a threshold of about 820M is reached. At this point the memory
seems to be getting reclaimed (both the Garbage Collector and CPU
usage are more active).

The Astra LoadTest tool shows that there response time for the pages
progressively decreases from about 10 seconds to about 35 seconds.

I have a picture of the PerfMon results if you want to see it (please
email me for this).


My questions are:

Is this pattern of memory usage ‘normal'? Does the amount of memory
used increase until there is little remaining, so the Garbage
Collector then has to do a lot of work?

Is this a memory leak or not?

Thanks
Ian

 

[Pavel Lebedinsky]

It could be anything - a memory leak in your code, a bug in
ASP.NET or CLR or simply too much load for the GC to handle.

I'd suggest that you read this article and try the troubleshooting
steps described in it:

Production Debugging for .NET Framework Applications
Debugging Memory Problems

http://msdn.microsoft.com/library/en-us/dnbda/html/DBGch02.asp?frame=true

 

[ianstirkcv]

Hi,

thanks for your reply.

It seems the problem is because the Trace flag was set on in the Release build.

Ian

 

[Nir]

! -- It seems the problem is because the Trace flag was set on in the Release

Hello ,

would U explain Pls. what is "Trace flag" it may help me too

Thank U

Nir Salab
Zomet Information LTD.
(e-mail address removed)