How to research unmanaged memory leaks in .NET?

Brandon picture Brandon · May 17, 2010 · Viewed 15.8k times · Source

I have a WCF service running over MSMQ. Memory gradually increases over time, indicating that there is some sort of memory leak. I ran the service locally and monitored some counters using PerfMon. Total CLR memory managed heap bytes remains relatively constant, while the process' private bytes increases over time. This leads me to believe that there is some sort of unmanaged memory leak. Assuming that unmanaged memory leak is the issue, how do I address the issue? Are there any tools I could use to give me hints as to what is causing the unmanaged memory leak? Also, all my service is doing is reading from the transactional queue and writing to a database, all as part of a DTC transaction (handled under the hood by requiring a transaction on the service contract). I am not doing anything explicitly with COM or DllImports.

Thanks in advance!

Answer

Remus Rusanu picture Remus Rusanu · May 17, 2010

You can use Windbg to analyze the process Heap. There are some articles and cheat sheets showing how to do this, like Memory Leak Detection Using Windbg