problem with .net remoting - SQL Server

[jdccr]

Hi, I am using .NET Remoting for database connection.

I have three components:

1. A class library 'RemoteComponent.dll':

Imports System
Imports System.Data.SqlClient
Imports System.Runtime.Remoting
Imports System.Runtime.Remoting.Channels
Imports System.Runtime.Remoting.Channels.Tcp

Public Class RemoteClass
Inherits MarshalByRefObject

Public Function ConnectionString() As String
Return "user id=sa;password=;Database=Northwind;Server=localhost;Connect Timeout=30"
End Function

Public Overloads Function RunSQL( _
ByVal cSQL As String, _
ByVal cTableName As String) As DataSet

Dim oCmd As SqlCommand = New SqlCommand
Dim oCnn As SqlConnection = Nothing
Dim oAdp As SqlDataAdapter = New SqlDataAdapter
Dim oDs As DataSet = New DataSet

Try
oCnn = New SqlConnection(ConnectionString)

With oCmd
.Connection = oCnn
.CommandText = cSQL
.CommandType = CommandType.Text
End With

With oAdp
.SelectCommand = oCmd
.Fill(oDs, cTableName)
End With

If Not oCnn Is Nothing And oCnn.State <> ConnectionState.Closed Then
oCnn.Close()
End If

Return oDs

Catch ex As Exception
Throw New System.Exception(ex.Message)
End Try
End Function
End Class

2. A console application 'Listener.exe':

Imports System
imports System.Runtime.Remoting
Imports System.Runtime.Remoting.Channels
Imports System.Runtime.Remoting.Channels.Tcp
Imports System.Runtime.Remoting.Channels.Http

Public Class Listener
Public Shared Function Main(ByVal args() As String) As Integer
Dim channel As TcpChannel = New TcpChannel(8080)
ChannelServices.RegisterChannel(channel)

RemotingConfiguration.RegisterWellKnownServiceType( _
GetType(RemoteComponent.RemoteClass), _
"RemoteComponent.RemoteClass", _
WellKnownObjectMode.SingleCall)

System.Console.WriteLine("Press the enter key to exit...")
System.Console.ReadLine()
Return 0
End Function
End Class

3. A windows application client.exe:

Private Sub Form1_Load(ByVal sender As Object, ByVal e As System.EventArgs) Handles MyBase.Load
Dim chan As TcpChannel = New TcpChannel
ChannelServices.RegisterChannel(chan)

Dim oRemoteClass As RemoteComponent.RemoteClass = CType(Activator.GetObject( _
GetType(RemoteComponent.RemoteClass), _
"tcp://omega:8080/RemoteComponent.RemoteClass"), RemoteComponent.RemoteClass)

If oRemoteClass Is Nothing Then
System.Console.WriteLine("Error: unable to locate server")
Else
Dim cSQL As String
Dim dsData As DataSet

cSQL = " select *"
cSQL = cSQL & " from customers"

dsData = oRemoteClass.RunSQL(cSQL, "Customers")

With Me.ComboBox
.ValueMember = dsData.Tables("Customers").Columns("CustomerId").ColumnName
.DisplayMember = dsData.Tables("Customers").Columns("CompanyName").ColumnName
.DataSource = dsData.Tables("Customers").DefaultView
End With

End If
ChannelServices.UnregisterChannel(chan)
End Sub

I execute two or more instance of my client. In the database I see only one session (commant sp_who in SQL Server) for the NorthWind database.

I need one session for each instance of my client application!!!

Thanks for your help!!!

 

[Mister E]

It's probably because the local database only sees the local class instance. It does not know requests are being initiated from a remote client.

 

[Joe Mamma]

you are only seeing a single instance because you are using a single call and the call is happening in a single thread.
it opens . . . it closes. only one session at a time is being created.

 

[jdccr]

I have a doubt

Ok, you are right, but I have a doubt:

If I don't use .NET Remoting and build the instance of RemoteClass in the following form:

Dim oRemoteClass As New RemoteComponent.RemoteClass

and If I execute two or more instances of my client application I see one session for each instance of my client application in the database.

The question is: Is there any way to obtain this behavior with .NET Remoting???

you are only seeing a single instance because you are using a single call and the call is happening in a single thread.
it opens . . . it closes. only one session at a time is being created.