.NET Remoting

1
.NET Remoting

• A Distributed Application Cookbook

2
Agenda

• Brief overview of Remoting
• Technicalities for creating a distributed
  application based on Remoting
• Examples has been uploaded to the course site

3
Remoting

• RMI Remote Method Invocation (JAVA)
• RPC Remote Procedure Call (.NET)

Costumizable!
Client
Server
Remote invocation
f
y
f(x)
Object
h
On runtime transparent to client
Standard development syntax
4
Step 1

• Create three modules
• A client module
• Holds client code
• Will ultimately run the client process (console
  application)
• A server module
• Holds server code
• Will ultimately run the server process (console
  application)
• A common library
• This module contains all the declarations\definit
  ions that are common to the client and the server
  (DLL)

5
Step 2 Creating the remote object

• In the common library module Declare an interface
  exposing your remote objects methods
• In the server module, declare the objects class
  extending MarshalByRefObject and implementing the
  interface

6
Step 3 Hosting the object

• The object is hosted in the server process
• Programmatically
• Using a configuration file

BinaryServerFormatterSinkProvider
serverSinkProvider new BinaryServerFormatterSink
Provider() serverSinkProvider.TypeFilterLevel
System.Runtime.Serialization.Formatters.TypeFilter
Level.Full IDictionary prop new
Hashtable() prop"port" 9999 // listen on
a specific port ChannelServices.RegisterChannel(n
ew TcpChannel(prop, null, serverSinkProvider),
false) RemotingConfiguration.RegisterWellKnownSe
rviceType( Type.GetType("Serve
r.Program"), "Service",
WellKnownObjectMode.Singleton)
7
Step 4 Instantiation at the client

• The object is instantiated and accessed in the
  client process
• Programmatically
• Using a configuration file

BinaryClientFormatterSinkProvider
clientSinkProvider new BinaryClientFormatterSink
Provider() clientSinkProvider.TypeFilterLevel
System.Runtime.Serialization.Formatters.TypeFilter
Level.Full IDictionary prop new
Hashtable() prop"port" 0 // open an
arbitrary port ChannelServices.RegisterChannel(ne
w TcpChannel(prop, clientSinkProvider, null),
false) Common.IService service
(Common.IService)Activator.GetObject(typeof(Common
.IService),
"tcp//localhost9999/Service")
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Custom Sinks
BinaryFormatter
9
Custom Sinks

• A class implementing the sink
• Extend BaseChannelSinkWithProperties
• Implement IClientChannelSink or
  IserverChannelSink
• Implement IMessageSink if placed before the
  formatter sink
• A sink provider class
• Implementing IClientChannelSinkProvider or
  IServerChannelSinkProvider
• Actually passed to the channel

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Custom Sinks Usage

• public IMessage SyncProcessMessage(IMessage
  reqMsg)
• destURI DataServersManager.GetAvailab
  leDataServer()
• reqMsg.Properties"__Uri"
  destURI
• // create new next sink with new
  URI
• nextSink nextSinkProvider.CreateSi
  nk(channel, destURI.ToString(), null)
• Console.WriteLine("Going to send request to "
  (string)reqMsg.Properties"__Uri")
• IMethodReturnMessage returnMessage
  NextSink.SyncProcessMessage(reqMsg)
• return returnMessage