.NET Memory Leak

Question

After running our stress testing on our ASP.NET application access to internal web services, our mid-tier server (where we host ASMX .NET 3.5 web services) showed close to 1GB of memory consumption.

Upon the review of memory dump from mid-tier server, I have found over 1000 objects of Microsoft.Xml.Serialization.GeneratedAssembly.ArrayOfObjectSerializer referenced by Web Services runtime itself.

Is this anything related to how our custom objects are getting serialized/deserialized in the web services layer? Could anyone shed more light on this?

When I did !gcroot on some of these 1000 objects, I got the following trace: (Microsoft.Practices.EnterpriseLibrary.Common.Configuration.Storage.ConfigurationChangeFileWatcher)-> 1c4bb450(System.Threading.Thread)-> 18236aa0(System.Runtime.Remoting.Contexts.Context)-> 18236914(System.AppDomain)-> 10409dc4(System.ResolveEventHandler)-> 10409494(System.Web.Compilation.BuildManager)-> 10409f30(System.Web.Compilation.MemoryBuildResultCache)-> 103d115c(System.Web.Caching.CacheMultiple)-> 103d1174(System.Object[])-> 103d2034(System.Web.Caching.CacheSingle)-> 103d2080(System.Collections.Hashtable)-> 1c24b97c(System.Collections.Hashtable+bucket[])-> 1c24b934(System.Web.Caching.CacheEntry)-> 18363994(System.Web.Services.Protocols.SoapServerType)-> 183639c4(System.Collections.Hashtable)-> 1c24aa5c(System.Collections.Hashtable+bucket[])-> 1c24a458(System.Web.Services.Protocols.SoapServerMethod)-> 1c248ae4(Microsoft.Xml.Serialization.GeneratedAssembly.ArrayOfObjectSerializer26)

(Microsoft.Practices.EnterpriseLibrary.Common.Configuration.Storage.ConfigurationChangeFileWatcher)-> 1c5ac4b0(System.Threading.Thread)-> 1c52b5f0(System.Runtime.Remoting.Contexts.Context)-> 1c52b464(System.AppDomain)-> 18823880(System.ResolveEventHandler)-> 18822f50(System.Web.Compilation.BuildManager)-> 188239e0(System.Web.Compilation.MemoryBuildResultCache)-> 144631fc(System.Web.Caching.CacheMultiple)-> 14463214(System.Object[])-> 14465088(System.Web.Caching.CacheSingle)-> 144650d4(System.Collections.Hashtable)-> 1446510c(System.Collections.Hashtable+bucket[])-> 1c5a580c(System.Web.Caching.CacheEntry)-> 109e6e34(System.Web.Services.Protocols.SoapServerType)-> 109e6e64(System.Collections.Hashtable)-> 1c5a4fcc(System.Collections.Hashtable+bucket[])-> 1c5a4a54(System.Web.Services.Protocols.SoapServerMethod)-> 1c5a44f4(Microsoft.Xml.Serialization.GeneratedAssembly.ArrayOfObjectSerializer28)

(Microsoft.Practices.EnterpriseLibrary.Common.Configuration.Storage.ConfigurationChangeFileWatcher)-> 108b38f0(System.Threading.Thread)-> 1c1155ec(System.Runtime.Remoting.Contexts.Context)-> 1c115460(System.AppDomain)-> 1030d348(System.ResolveEventHandler)-> 1030ca18(System.Web.Compilation.BuildManager)-> 1030d4a0(System.Web.Compilation.MemoryBuildResultCache)-> 102d7ae4(System.Web.Caching.CacheMultiple)-> 102d7afc(System.Object[])-> 102d7b1c(System.Web.Caching.CacheSingle)-> 102d7b68(System.Collections.Hashtable)-> 102d7bac(System.Collections.Hashtable+bucket[])-> 181ee124(System.Web.Caching.CacheEntry)-> 10350eac(System.Web.Services.Protocols.SoapServerType)-> 10350edc(System.Collections.Hashtable)-> 181ed260(System.Collections.Hashtable+bucket[])-> 181ed148(System.Web.Services.Protocols.SoapServerMethod)-> 181eb708(Microsoft.Xml.Serialization.GeneratedAssembly.ArrayOfObjectSerializer61)

Thanks BK

Answer 1

You might want to try instrumenting your code with ANTS Memory Profiler from Red Gate.

Answer 2

I would strongly recommend us of the simply named .Net Memory Profiler from http://memprofiler.com/download.aspx.

You can use the full version for 14 days for free.

I have found it useful for this type of problem solving. It will show you the reference tree. Making fixing these type of problems really easy.