I am trying to move my app to out-of-proc session state and can't find which session object is failing to serialize - the YSOD stack trace is unrevealing.
Is it possible to view the objects, or at least the types of objects, currently stored in session state of a running application? Short of attaching a debugger to a running app, and having its source code available, I don't know if this is possible.
I'm using Alachisoft NCache, so here's their stack trace, though it's not helpful:
System.Web.HttpException (0x80004005): Unable to serialize the session state. In 'StateServer' and 'SQLServer' mode, ASP.NET will serialize the session state objects, and as a result non-serializable objects or MarshalByRef objects are not permitted. The same restriction applies if similar serialization is done by the custom session state store in 'Custom' mode. ---> System.Runtime.Serialization.SerializationException: Type 'System.Web.UI.Control' in Assembly 'System.Web, Version=4.0.0.0, Culture=neutral, PublicKeyToken=b03f5f7f11d50a3a' is not marked as serializable.
at System.Runtime.Serialization.FormatterServices.InternalGetSerializableMembers(RuntimeType type)
at System.Runtime.Serialization.FormatterServices.GetSerializableMembers(Type type, StreamingContext context)
at System.Runtime.Serialization.Formatters.Binary.WriteObjectInfo.InitMemberInfo()
at System.Runtime.Serialization.Formatters.Binary.WriteObjectInfo.InitSerialize(Object obj, ISurrogateSelector surrogateSelector, StreamingContext context, SerObjectInfoInit serObjectInfoInit, IFormatterConverter converter, ObjectWriter objectWriter, SerializationBinder binder)
at System.Runtime.Serialization.Formatters.Binary.ObjectWriter.Write(WriteObjectInfo objectInfo, NameInfo memberNameInfo, NameInfo typeNameInfo)
at System.Runtime.Serialization.Formatters.Binary.ObjectWriter.Serialize(Object graph, Header[] inHeaders, __BinaryWriter serWriter, Boolean fCheck)
at System.Runtime.Serialization.Formatters.Binary.BinaryFormatter.Serialize(Stream serializationStream, Object graph, Header[] headers, Boolean fCheck)
at System.Web.Util.AltSerialization.WriteValueToStream(Object value, BinaryWriter writer)
at System.Web.Util.AltSerialization.WriteValueToStream(Object value, BinaryWriter writer)
at System.Web.SessionState.SessionStateItemCollection.WriteValueToStreamWithAssert(Object value, BinaryWriter writer)
at System.Web.SessionState.SessionStateItemCollection.Serialize(BinaryWriter writer)
at Alachisoft.NCache.Web.SessionState.SessionSerializationUtil.Serialize(SessionStateStoreData sessionData)
at Alachisoft.NCache.Web.SessionState.NSessionStoreProvider.InsertContents(HttpContext context, SessionStateStoreData data, SessionStateActions flag, Int32 timeout)
at Alachisoft.NCache.Web.SessionState.NSessionStoreProvider.SetAndReleaseItemExclusive(HttpContext context, String id, SessionStateStoreData items, Object lockID, Boolean newItem
UPDATE
I have the same results using SQL Server session state:
[SerializationException: Type 'System.Web.UI.Control' in Assembly 'System.Web, Version=4.0.0.0, Culture=neutral, PublicKeyToken=b03f5f7f11d50a3a' is not marked as serializable.]
System.Runtime.Serialization.FormatterServices.InternalGetSerializableMembers(RuntimeType type) +12475327
System.Runtime.Serialization.FormatterServices.GetSerializableMembers(Type type, StreamingContext context) +361
System.Runtime.Serialization.Formatters.Binary.WriteObjectInfo.InitMemberInfo() +413
System.Runtime.Serialization.Formatters.Binary.WriteObjectInfo.InitSerialize(Object obj, ISurrogateSelector surrogateSelector, StreamingContext context, SerObjectInfoInit serObjectInfoInit, IFormatterConverter converter, ObjectWriter objectWriter, SerializationBinder binder) +556
System.Runtime.Serialization.Formatters.Binary.ObjectWriter.Write(WriteObjectInfo objectInfo, NameInfo memberNameInfo, NameInfo typeNameInfo) +969
System.Runtime.Serialization.Formatters.Binary.ObjectWriter.Serialize(Object graph, Header[] inHeaders, __BinaryWriter serWriter, Boolean fCheck) +1016
System.Runtime.Serialization.Formatters.Binary.BinaryFormatter.Serialize(Stream serializationStream, Object graph, Header[] headers, Boolean fCheck) +319
System.Web.Util.AltSerialization.WriteValueToStream(Object value, BinaryWriter writer) +1559
[HttpException (0x80004005): Unable to serialize the session state. In 'StateServer' and 'SQLServer' mode, ASP.NET will serialize the session state objects, and as a result non-serializable objects or MarshalByRef objects are not permitted. The same restriction applies if similar serialization is done by the custom session state store in 'Custom' mode.]
System.Web.Util.AltSerialization.WriteValueToStream(Object value, BinaryWriter writer) +2273923
System.Web.SessionState.SessionStateItemCollection.WriteValueToStreamWithAssert(Object value, BinaryWriter writer) +49
System.Web.SessionState.SessionStateItemCollection.Serialize(BinaryWriter writer) +811
System.Web.SessionState.SessionStateUtility.Serialize(SessionStateStoreData item, Stream stream) +342
System.Web.SessionState.SessionStateUtility.SerializeStoreData(SessionStateStoreData item, Int32 initialStreamSize, Byte[]& buf, Int32& length, Boolean compressionEnabled) +99
System.Web.SessionState.SqlSessionStateStore.SetAndReleaseItemExclusive(HttpContext context, String id, SessionStateStoreData item, Object lockId, Boolean newItem) +3673544
System.Web.SessionState.SessionStateModule.OnReleaseState(Object source, EventArgs eventArgs) +929
System.Web.SyncEventExecutionStep.System.Web.HttpApplication.IExecutionStep.Execute() +80
System.Web.HttpApplication.ExecuteStep(IExecutionStep step, Boolean& completedSynchronously) +270