Too much memory usage of IIS application pool

iis

My Windows Server is running an web application on IIS 7.5.

I'm wondering why IIS application pools use a lot of memory.

Please refer to the screenshop I captured from the servere.

enter image description here

In the application pool named TEST 2.0 (.NET Framework Version 2.0), there is only one small web service. However, it takes about 3GB for Virtual Bytes.

Also, in the application pool named TEST 4.0 (.NET Framework Version 4.0), there is only one web service doing nothing. However, it allocates about 9GB for Virtual Bytes.

Do you know why IIS 7.5 occupies huge memory? What's the problem?

Do you have any intuitive ideas about it?

To give you more ideas, here is my system environment:

  • OS: Windows Server 2008 R2 Standard SP1
  • HW: Intel(R) Xeon(R) CPU X5670 @ 2.93GHz 2.93GHz / 8.0GB RAM


Best Answer

Short answer: Nothing is wrong :)

You are not actually using 2GB of RAM. That is merely the allowed address space for this process. Private Bytes is the measure of RAM usage (so, 90MB in this case).

From the PerfMon definition for Virtual Bytes:

Virtual Bytes - Virtual Bytes is the current size, in bytes, of the virtual address space the process is using. Use of virtual address space does not necessarily imply corresponding use of either disk or main memory pages. Virtual space is finite, and the process can limit its ability to load libraries.