I had previously read and heard in presentations by Rocky Lhotka that performance comparisons between Web Services and Remoting showed that they were basically the same, and that when talking about RPC protocols ES killed them both so badly (order of magnitude) that it wasn’t worth fretting over the small diff between WS and remoting.

Rocky kinda explains this position in this post:
http://www.lhotka.net/weblog/RemotingVsWebServicesVsESCOMDCOM.aspx

However, I actually tracked down the white paper on Microsofts website:
http://msdn.microsoft.com/library/default.asp?url=/library/en-us/dnwebsrv/html/asmxremotesperf.asp

Much to my suprise the giant performance improvement when using ES was only seen when calling empty functions.  In otherwords, it was basically a test of the transport.  Some “real world” tests showed ES performing faster than most other methods, but sometimes something like Remoting TCP Binary would outperform it as well.

In the tests that actually did something, the performance across the board was usually fairly comperable.  I guess this makes sense.  If you liken the round trip of an RPC call to a person going on a business trip, the speed of the airplane is less important that the time it takes the person to do the job at the end of the trip.  So even if your plane takes 3 hours instead of 2 hours, if your going to be staying for a week then that 1 hour isn’t a big deal.

The major conclusion is to not pass datasets.  Datasets are serialized as XML even if you are using the binary serializer.  I have posted some stuff on this topic as well on my blog so you can search for it if you want. 

Brad Abrams has a good article out there showing a list of all the .net exceptions you can throw from your code.

There are some exceptions that are not shown here, for example ConfigurationException, but this is a good starting point.

From Brad’s article:

+–System.Object  

   |

   |

   +–System.Exception  

       |

       |

       +–System.SystemException  

           |

           |

           +–System.ArgumentException  

           |   |

           |   |

           |   +–System.ArgumentNullException  

           |   |

           |   |

           |   +–System.ArgumentOutOfRangeException  

           |   |

           |   |

           |   +–System.DuplicateWaitObjectException  

           |

           |

           +–System.ArithmeticException  

           |   |

           |   |

           |   +–System.DivideByZeroException  

           |   |

           |   |

           |   +–System.OverflowException  

           |   |

           |   |

           |   +–System.NotFiniteNumberException

           |

           |

           +–System.ArrayTypeMismatchException  

           |

           |

           +–System.ExecutionEngineException  

           |

           |

           +–System.FormatException  

           |

           |

           +–System.IndexOutOfRangeException  

           |

           |

           +–System.InvalidCastException  

           |

           |

           +–System.InvalidOperationException  

           |   |

           |   |

           |   +–System.ObjectDisposedException  

           |

           |

           +–System.InvalidProgramException  

           |

           |

           +–System.IO.IOException  

           |   |

           |   |

           |   +–System.IO.DirectoryNotFoundException  

           |   |

           |   |

           |   +–System.IO.EndOfStreamException  

           |   |

           |   |

           |   +–System.IO.FileLoadException  

           |   |

           |   |

           |   +–System.IO.FileNotFoundException  

           |   |

           |   |

           |   +–System.IO.PathTooLongException  

           |

           |

           +–System.NotImplementedException  

           |

           |

           +–System.NotSupportedException  

           |

           |

           +–System.NullReferenceException  

           |

           |

           +–System.OutOfMemoryException  

           |

           |

           +–System.RankException  

           |

           |

           +–System.Security.SecurityException  

           |

           |

           +–System.Security.VerificationException  

           |

           |

           +–System.StackOverflowException  

           |

           |

           +–System.Threading.SynchronizationLockException  

           |

           |

           +–System.Threading.ThreadAbortException  

           |

           |

           +–System.Threading.ThreadStateException  

           |

           |

           +–System.TypeInitializationException  

           |

           |

           +–System.UnauthorizedAccessException 

Jeff Atwood put up another article where he uses a little console app to find all classes named “*Exception”. 

Here is his list:

System.AppDomainUnloadedException
System.ApplicationException
System.ArgumentException
System.ArgumentNullException
System.ArgumentOutOfRangeException
System.ArithmeticException
System.ArrayTypeMismatchException
System.BadImageFormatException
System.CannotUnloadAppDomainException
System.ComponentModel.Design.CheckoutException
System.ComponentModel.Design.Serialization.CodeDomSerializerException
System.ComponentModel.InvalidEnumArgumentException
System.ComponentModel.LicenseException
System.ComponentModel.WarningException
System.ComponentModel.Win32Exception
System.Configuration.ConfigurationException
System.ContextMarshalException
System.Data.ConstraintException
System.Data.DataException
System.Data.DBConcurrencyException
System.Data.DeletedRowInaccessibleException
System.Data.DuplicateNameException
System.Data.EvaluateException
System.Data.ExprException
System.Data.InRowChangingEventException
System.Data.InvalidConstraintException
System.Data.InvalidExpressionException
System.Data.MissingPrimaryKeyException
System.Data.NoNullAllowedException
System.Data.Odbc.OdbcException
System.Data.OleDb.OleDbException
System.Data.ReadOnlyException
System.Data.RowNotInTableException
System.Data.SqlClient._ValueException
System.Data.SqlClient.SqlException
System.Data.SqlTypes.SqlNullValueException
System.Data.SqlTypes.SqlTruncateException
System.Data.SqlTypes.SqlTypeException
System.Data.StrongTypingException
System.Data.SyntaxErrorException
System.Data.TypedDataSetGeneratorException
System.Data.VersionNotFoundException
System.DivideByZeroException
System.DllNotFoundException
System.Drawing.Printing.InvalidPrinterException
System.DuplicateWaitObjectException
System.EntryPointNotFoundException
System.Exception
System.ExecutionEngineException
System.FieldAccessException
System.FormatException
System.IndexOutOfRangeException
System.InvalidCastException
System.InvalidOperationException
System.InvalidProgramException
System.IO.DirectoryNotFoundException
System.IO.EndOfStreamException
System.IO.FileLoadException
System.IO.FileNotFoundException
System.IO.InternalBufferOverflowException
System.IO.IOException
System.IO.IsolatedStorage.IsolatedStorageException
System.IO.PathTooLongException
System.Management.ManagementException
System.MemberAccessException
System.Messaging.MessageQueueException
System.MethodAccessException
System.MissingFieldException
System.MissingMemberException
System.MissingMethodException
System.MulticastNotSupportedException
System.Net.CookieException
System.Net.ProtocolViolationException
System.Net.Sockets.SocketException
System.Net.WebException
System.NotFiniteNumberException
System.NotImplementedException
System.NotSupportedException
System.NullReferenceException
System.ObjectDisposedException
System.OutOfMemoryException
System.OverflowException
System.PlatformNotSupportedException
System.RankException
System.Reflection.AmbiguousMatchException
System.Reflection.CustomAttributeFormatException
System.Reflection.InvalidFilterCriteriaException
System.Reflection.ReflectionTypeLoadException
System.Reflection.TargetException
System.Reflection.TargetInvocationException
System.Reflection.TargetParameterCountException
System.Resources.MissingManifestResourceException
System.Runtime.InteropServices.COMException
System.Runtime.InteropServices.ExternalException
System.Runtime.InteropServices.InvalidComObjectException
System.Runtime.InteropServices.InvalidOleVariantTypeException
System.Runtime.InteropServices.MarshalDirectiveException
System.Runtime.InteropServices.SafeArrayRankMismatchException
System.Runtime.InteropServices.SafeArrayTypeMismatchException
System.Runtime.InteropServices.SEHException
System.Runtime.Remoting.MetadataServices.SUDSGeneratorException
System.Runtime.Remoting.MetadataServices.SUDSParserException
System.Runtime.Remoting.RemotingException
System.Runtime.Remoting.RemotingTimeoutException
System.Runtime.Remoting.ServerException
System.Runtime.Serialization.SerializationException
System.Security.Cryptography.CryptographicException
System.Security.Cryptography.CryptographicUnexpectedOperationException
System.Security.Policy.PolicyException
System.Security.SecurityException
System.Security.VerificationException
System.Security.XmlSyntaxException
System.ServiceProcess.TimeoutException
System.StackOverflowException
System.SystemException
System.Threading.SynchronizationLockException
System.Threading.ThreadAbortException
System.Threading.ThreadInterruptedException
System.Threading.ThreadStateException
System.Threading.ThreadStopException
System.TypeInitializationException
System.TypeLoadException
System.TypeUnloadedException
System.UnauthorizedAccessException
System.UriFormatException
System.Web.HttpApplication+CancelModuleException
System.Web.HttpCompileException
System.Web.HttpException
System.Web.HttpParseException
System.Web.HttpRequestValidationException
System.Web.HttpUnhandledException
System.Web.Services.Discovery.InvalidContentTypeException
System.Web.Services.Discovery.InvalidDocumentContentsException
System.Web.Services.Protocols.SoapException
System.Web.Services.Protocols.SoapHeaderException
System.Windows.Forms.AxHost+InvalidActiveXStateException
System.Xml.Schema.XmlSchemaException
System.Xml.XmlException
System.Xml.XPath.XPathException
System.Xml.Xsl.XsltCompileException


The code used to create this list (.net 1.1) is:


    Sub Main()
        ReflectionSearch(".*exception$")
        Console.ReadLine()
    End Sub

    Sub ReflectionSearch(ByVal strPattern As String)
        Dim a As Reflection.Assembly
        Dim m As Reflection.Module
        Dim t As Type
        Dim al As New ArrayList
        Dim sl As New SortedList
        Dim strAssemblyName As String

        For Each strAssemblyName In DefaultAssemblyList()
            a = Reflection.Assembly.Load(strAssemblyName)
            For Each m In a.GetModules
                For Each t In m.GetTypes
                    al.Add(t)
                    Dim strFullName As String = t.FullName
                    If Regex.IsMatch(strFullName, strPattern, RegexOptions.IgnoreCase) Then
                        sl.Add(strFullName, Nothing)
                    End If
                Next
            Next

  Next

        Dim de As DictionaryEntry
        For Each de In sl
            Console.WriteLine(de.Key)
        Next
        Console.WriteLine(sl.Count.ToString & " matches for " & strPattern)
    End Sub

    Function DefaultAssemblyList() as ArrayList
        Dim al As New ArrayList
        With al
            .Add("mscorlib, Version=1.0.5000.0, Culture=neutral, PublicKeyToken=b77a5c561934e089")
            .Add("System.Data, Version=1.0.5000.0, Culture=neutral, PublicKeyToken=b77a5c561934e089")
            .Add("System, Version=1.0.5000.0, Culture=neutral, PublicKeyToken=b77a5c561934e089")
            .Add("System.Runtime.Remoting, Version=1.0.5000.0, Culture=neutral, PublicKeyToken=b77a5c561934e089")
            .Add("System.Windows.Forms, Version=1.0.5000.0, Culture=neutral, PublicKeyToken=b77a5c561934e089")
            .Add("System.Xml, Version=1.0.5000.0, Culture=neutral, PublicKeyToken=b77a5c561934e089")
            .Add("System.Design, Version=1.0.5000.0, Culture=neutral, PublicKeyToken=b03f5f7f11d50a3a")
            .Add("System.DirectoryServices, Version=1.0.5000.0, Culture=neutral, PublicKeyToken=b03f5f7f11d50a3a")
            .Add("System.Drawing.Design, Version=1.0.5000.0, Culture=neutral, PublicKeyToken=b03f5f7f11d50a3a")
            .Add("System.Drawing, Version=1.0.5000.0, Culture=neutral, PublicKeyToken=b03f5f7f11d50a3a")
            .Add("System.Messaging, Version=1.0.5000.0, Culture=neutral, PublicKeyToken=b03f5f7f11d50a3a")
            .Add("System.Runtime.Serialization.Formatters.Soap, Version=1.0.5000.0, Culture=neutral, PublicKeyToken=b03f5f7f11d50a3a")
            .Add("System.Security, Version=1.0.5000.0, Culture=neutral, PublicKeyToken=b03f5f7f11d50a3a")
            .Add("System.ServiceProcess, Version=1.0.5000.0, Culture=neutral, PublicKeyToken=b03f5f7f11d50a3a")
            .Add("System.Web, Version=1.0.5000.0, Culture=neutral, PublicKeyToken=b03f5f7f11d50a3a")
            .Add("System.Web.Services, Version=1.0.5000.0, Culture=neutral, PublicKeyToken=b03f5f7f11d50a3a")
            .Add("System.Management, Version=1.0.5000.0, Culture=neutral, PublicKeyToken=b03f5f7f11d50a3a")
        End With
        Return al
    End Function

System.Xml.Xsl.XsltException

Microsoft has released LINQ CTP.

While it is not expected that this will become fully released until the next version of Visual Studio (2008?) it is not something bad to look at now.

CSLA as well as well as the proxy architecture I created for my last project, utilize serialization of objects to be passed across the wire, and deserialized on the other side into the same type of object.

This is different from passing datasets, which are then read into business objects.  We are actually passing the serialized version of the business object.

So what happens if you make a change to a business object such as adding a public property.  Will clients who have the old version of the Business Object be forced to upgrade? 

To see the answers along with some sample code for testing this out click on the link to read the full article.

So lets say you have a class that exposes 20 properties and 40 methods.  This business object is deployed on hundreds of clients computers.  When they send the BizObject over the wire, it is deserialized back into the exact same object on the server. 

But now, for whatever reason, you need to add 1 property to this BizObject.  For the current set of clients using this business object, you don’t really need to deploy the updated change unless you have to in order to keep it from breaking.

So do you need to redeploy?  Probably not.

I serialzied a business object into a base64 encoded string and then added a public property to the object and tried to deserialize it with the “old” serialized string.  The result?  It worked.  The properties that had values when I first serialized it kept their values.  The fact that there were new properties didn’t cause a problem.

How about going the other way: removing a public property that had a value when it was serialized, but doesn’t exist with deserialized.  Again, this works. 

When doesn’t it work?  When you are trying to deserialze into a different class, or a different namespace for the same class. 

So you can’t serialize classA and deserialize it into classB, even if both expose the exact same signature.  The same goes for namespaces.  If you serialize classA, and then change it’s namespace and try to deserialize it, you will get an exception.

You can try it out with the following code:

Imports WindowsApplication1.ASDF


Public Class Form1

    Private Sub toString_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles cmdToString.Click
        Dim o As New A
        o.A11 = "this is a test"
        o.Asdf1 = "another test"

        Me.TextBox2.Text = EncodeBase64(o.CloneString)
        MsgBox(EncodeBase64(o.CloneString))
    End Sub

    Private Sub fromString_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles fromString.Click
        Dim o As A = A.Hydrate(DecodeBase64(Me.TextBox1.Text))
        MsgBox(o.A11)
        MsgBox(o.Asdf1)
        MsgBox(o.asdfdsa)
    End Sub

    Public Function EncodeBase64(ByVal input As String) As String
        Dim strBytes() As Byte = System.Text.Encoding.UTF8.GetBytes(input)
        Return System.Convert.ToBase64String(strBytes)
    End Function

    Public Function DecodeBase64(ByVal input As String) As String
        Return System.Text.Encoding.UTF8.GetString(System.Convert.FromBase64String(input))
    End Function

End Class


<Serializable()> _
Public Class Parent

    Public Function CloneString() As String
        Dim bFormatter As New System.Runtime.Serialization.Formatters.Binary.BinaryFormatter
        Dim stream As New System.IO.MemoryStream()
        bFormatter.Serialize(stream, Me)
        stream.Flush()
        stream.Position = 0
        Dim bytes() As Byte = stream.ToArray()

        Return System.Text.Encoding.Default.GetString(bytes)
    End Function

    Public Shared Function StringToStream(ByVal str As String) As System.IO.Stream
        Return New System.IO.MemoryStream(System.Text.Encoding.Default.GetBytes(str))
    End Function

End Class

<Serializable()> _
Public Class A
    Inherits Parent

    Private a1 As String
    Private asdf As String
    Public Property A11() As String
        Get
            Return a1
        End Get
        Set(ByVal value As String)
            a1 = value
        End Set
    End Property

    Public Property Asdf1() As String
        Get
            Return asdf
        End Get
        Set(ByVal value As String)
            asdf = value
        End Set
    End Property
    Public Function asdfdsa() As String
        Return "Asdf"
    End Function
    Public Shared Function Hydrate(ByVal s As String) As A
        Dim bFormatter As New System.Runtime.Serialization.Formatters.Binary.BinaryFormatter
        Dim stream2 As System.IO.MemoryStream = StringToStream(s)
        stream2.Flush()
        stream2.Position = 0
        Dim newClone As A
        newClone = CType(bFormatter.Deserialize(stream2), A)
        Return newClone
    End Function

End Class

I was able to get to the CNUG meeting where Rocky Lhotka was the feature speaker.

I had a chance to ask Rocky a couple of questions that had been bugging me about CSLA.

1)  He agreed that using the method of multiple result sets in datareader is not really a good idea in some instances, where a dataset would be much more useful.

2)  He suggested that you should usually not have an object that is sometimes a child and sometimes a parent.  I am not sure I agree with idea.  I believe I understand his point that if you are dealing with a Project object that has a collection of Employees assigned to it, you probably don’t need the Employees to be as complex as if you were dealing with an Employee who is assigned to a bunch of Projects, but at the same time you are talking about writing 2 classes with 2 sets of data access scripts, vs 4 classes and 4 sets of data access.  But, he said that there are techniques for making a business object be both a parent and a child.  This is apparently detailed in Ch 7. 

Rocky suggested the book Object Thinking by Dave West

3) He mentioned that people have built UI Frameworks that run on top of CSLA.  I will have to look into this.

4) He was showing an example using an ASP.NET MultiView control, looked like a great way to enable multiple views of the same data.

5) I didn’t get a chance to ask him about serialization and deserialization of classes that have small differences.  For example if you serialze an object and use the same byte array to deserialize a similar class, will it blow up if small changes are made, like you add a public property?  I will have to try this out myself.

In all, Rocky was a very good speaker.  Very engaging, funny, and on point. 

Oh and I won the raffle at the end, to get a copy of his book, the one I just paid 60 bucks for :-).