WCF Windows Service not releasing resources/memory after every call.

Question

I have created WCF application which is running on Windows Service. It was installed using Windows Installer. I have followed procedure mentioned in following article for same.

http://msdn.microsoft.com/en-us/library/bb332338.aspx#msdnwcfhc_topic4

Most WCF properties are kept as default for net.tcp protocol, per call instance and so on.

Memory consumption of service keeps on increasing after every call and does not decrease. At the end it throws OutOfMemory consumption.

Application returns very heavy string based data. With memory-profiler I found memory is still allocated to string objects and increases during call.

As per my understanding string is managed objects should release data once out of scope.

Let me know if any other configuration/coding information is needed specifically.

Answer 1

There must be something keeping references to those strings in the code. Can you use your profiler to trace the references that are keeping the string objects alive?

Answer 2

It would be very difficult to answer this question without some code to look at. You can always call GC.Collect(GC.MaxGeneration) to force garbage collection and see if this doesn't reduce your memory consumption. Ideally this would only be temporary code to track down what is going on in the application. If forcing garbage collection does not reduce memory consumption then references to the strings must be being retained, via static member variables or whatever: having no conception of what the code is, any theory would be a shot in the dark