presentation 23:.net remoting introduced objektorienteret middleware
TRANSCRIPT
Presentation 23:.NET Remoting Introduced
Objektorienteret Middleware
Outline
• .NET Framework introduced• .NET Remoting
• Strategies
• Architecture
• Remoting object types
• Activation
• Lifetime
• Deployment
• Example application
• Windows Communication Foundation short intro
Not a Windows .NET course
• You will NOT be required to be an expert on .NET• You will be required to be knowledgeable about it
• History:• Open source, Java, Linux the WWW threatened MS
• Especially Java was gaining widespread support amongst developers for its ease of use, productivity and heterogeneity
• The Empire Strikes back = the .NET Framework
Benefits of .NET
• Changes EVERYTHING• Takes all that was nice in Java and enhances it• End of DLL incompatibilities, DLL Hell, COM registry hell • Enter world of VM’s and Java like code (C#) including
Garbage collection – BUT with easy support for legacy unmanaged code (e.g. C++ for speed) and COM
• Performs much better than Java, and almost equivalent with Win32 C++ applications
• Still only support Microsoft operating systems BUT• .NET and C# is ECMA standard: Mono (www.go-mono.org)
for Linux is being developed. • IIOP.NET (http://iiop-net.sourceforge.net/index.html) for CORBA interop
.NET Framework
Win32Win32
MessageMessageQueuingQueuing
COM+COM+(Transactions, Partitions, (Transactions, Partitions,
Object Pooling)Object Pooling)IISIIS WMIWMI
Common Language RuntimeCommon Language Runtime
.NET Framework Class Library.NET Framework Class Library
ADO.NET and XMLADO.NET and XML
XML Web ServicesXML Web Services User InterfaceUser Interface
VisualBasic C++ C# Perl JScript …
Application services. E.g. IIS, Message Queuing etc.
CLR:runtime execution environment. Equlas JVM of Java. Microsoft Intermediate Language (MSIL) equals Java ByteCode
A collection of class libraries (over 9000) wraps Win32 like Java API
ActiveX Data Objects
3 types of user interfaces: Web forms, Windows forms (Win32), Command Console
For inter-process communications
Any language conforming to the Common Language Specification (CLS) may be used.
Sourcecode
Sourcecode CompilerCompiler
IntermediateLanguage
IntermediateLanguage
.NETFramework
.NETFramework
Other ILlibrariesOther ILlibraries
LinkerLinkerLinked
ProgramLinked
Program JIT-compilerJIT-compilerExecutableProgram
ExecutableProgram
Here we find the .NET Remoting libraries
Strategies• Two .NET Remoting strategies:
• Web services for inter-business purposes• Is heterogeneous across platforms and languages• Supported by the .NET compact framework• Relies primarily on HTTP/SOAP protocols, • May be adapted for any type of protocol • Heterogeneous • Is slow when used with HTTP/SOAP
• .NET Remoting for intra-business purposes • Is only heterogeneous across CLS languages• Not supported by the .NET compact framework• Relies on either HTTP/SOAP or TCP/Binary protocols,• May be adapted for any type of protocol • Is fast when used with TCP/Binary• Only heterogeneity within .NET runtime• In many ways very similar to Java RMI in Java 5
Simplified .NET Remoting Architecture
Using the classic Proxy patternUsing the classic Proxy pattern
The Remoting System wraps most of the marshalling/unmarshalling work for you – like CORBAThe Remoting System wraps most of the marshalling/unmarshalling work for you – like CORBA
Channel:
Takes a stream of data and transports it to another computer or process:
Default: TcpChannel & HttpChannel
Channel:
Takes a stream of data and transports it to another computer or process:
Default: TcpChannel & HttpChannel
The Remoting Architecture
Proxy created dynamically by the CLR. Creates a message to the server
Proxy created dynamically by the CLR. Creates a message to the server
Serializes the message into a stream (SOAP or binary)
Serializes the message into a stream (SOAP or binary)
Optional extra handlingOptional extra handling
Writes the stream to the wire, e.g. TCP or HTTP
Writes the stream to the wire, e.g. TCP or HTTP
Deserializes the messageDeserializes the message
Developers are free to implement new channels or replace sink elementsDevelopers are free to implement new channels or replace sink elements
All server objects must be of type MarshalByRefObject or an descendant hereof
All server objects must be of type MarshalByRefObject or an descendant hereof
Dispatch to server objectDispatch to server object
Remotable Objects in .NET Remoting
• Marshal-by-reference objects• By-reference – no state is transferred• MarshalByRefObject • Corresponds to CORBA Interface IDL and Java RMI Remote
objects (UnicastRemote objects)• Proxy created
• Marshal-by-value objects• By-value – complete object is serialized and transferred• Implements ISerializable or decorated with Serializable
Attribute [Serializable]• Very similar to Java RMI Serializable objects• Some similarity with CORBA valuetypes (Objects by Value)
Activation
• All server objects needs to be activated before a client proxy may access it
• Two types of activation• Server Activation (SAO)
• Activated when first client request arrives at server– Singleton: only one server instance for all clients– Single-call: a new server object pr. client request
• Lifetime is defined by server• Client Activation (CAO)
• Activated by the client with the CreateInstance method on the Activator object
• Server object only associated with creating client• Lifetime is controlled by client (using leases)
• Very different semantics than CORBA & RMI – closer to Web services (application, session, request scope) especially SAO
Lifetime management
• .NET Remoting uses leases for lifetime management• All server objects has a lifetime lease – a time-to-live• Lease manager
• controls the server object leases• If expired – check all sponsors (clients)• performs garbage collection on server objects
• In DCOM • reference counting & pinging
• In CORBA• ORB vendor specific• Often implemented as “time since last request”
• In Java RMI• uses leases (similar to .NET Remoting). Clients auto-update lease at
50%• Web services
• Toolkit specific (HTTP primitives: Application, Session, Request)• Application scope = runs for-ever / singleton
Configuration
• Configuration:• Need to inform runtime which servers are available and
at which address (URL)
• Two types of configuration• Programmatic (shown in example next)
• Configuration file
• Web.config (e.g. with IIS) or Machine.config
Deployment
• Server objects may be deployed as:• Windows Form application
• Windows Console application
• Windows Service
• Internet Information Server deployment
• no need for a server bootstrapping application
InterfaceDefinition
Design
Server StubGeneration
Client StubGeneration
ServerCoding
ClientCoding
ServerRegistration
Development Steps – Remoting vs. CORBA & Java RMI
Java RMI: rmicJava RMI: rmic
RMI: JAVARMI: JAVA
J2SE JDKJ2SE JDK
Start with Server Interface Coding: JAVA
Start with Server Interface Coding: JAVA
rmiregistryrmiregistry
CORBACORBA
CORBA: IDLCORBA: IDL
CORBA: IDLCORBA: IDL
ORBORB
RMI: JAVA interfaceRMI: JAVA interface
C++, Java …C++, Java …
C++, Java …C++, Java …
CLS InterfaceCLS Interface
Implicit stub gen.Implicit stub gen.
CLS (C# …)CLS (C# …)
CLS (C# …)CLS (C# …)
RemotingConfiguration
with CLR
RemotingConfiguration
with CLR
.NET Remoting
.NET Remoting
Making the HelloWorld App
• Using Microsoft Visual Studio .NET• may of course be done with .NET Framework alone
• Make Client & Server solutions• Server:
• IHelloWorld.cs interface• HelloWorld.cs class implementation• Server.cs class implementation for boot-strapping• Add Reference to assembly System.Runtime.Remoting
• Client• Must add IHelloWorld.cs• Client.cs class implementation• Add Reference to assembly System.Runtime.Remoting
The IHelloWorld Interface
using System;
namespace RemotingHelloServer{
// IHelloWorld is the interface for the HelloWorld server class.// It is the interface that is shared across the Internetpublic interface IHelloWorld{
string sayHello(string name); }
}
using System;
namespace RemotingHelloServer{
// IHelloWorld is the interface for the HelloWorld server class.// It is the interface that is shared across the Internetpublic interface IHelloWorld{
string sayHello(string name); }
}
The “IDL” of .NET Remoting – similar to Java RMI The “IDL” of .NET Remoting – similar to Java RMI
HelloWorld Implementation Code
using System;using System.Runtime.Remoting;
namespace RemotingHelloServer{
// HelloWorld is a server object that is available// "by-reference". It contains a constructor and a the// "sayHello" method taking a string parameter "name"public class HelloWorld : MarshalByRefObject, IHelloWorld{
private string greeting;
public HelloWorld(){
greeting = "OOMI Christsmas greetings from the server to: ";}
public string sayHello(string name) {
return (greeting + name);}
}}
using System;using System.Runtime.Remoting;
namespace RemotingHelloServer{
// HelloWorld is a server object that is available// "by-reference". It contains a constructor and a the// "sayHello" method taking a string parameter "name"public class HelloWorld : MarshalByRefObject, IHelloWorld{
private string greeting;
public HelloWorld(){
greeting = "OOMI Christsmas greetings from the server to: ";}
public string sayHello(string name) {
return (greeting + name);}
}}
Like in Java RMI (& CORBA) – we need to have an implementation of the interfaceLike in Java RMI (& CORBA) – we need to have an implementation of the interface
A remote object“by-reference” that
implements the IHelloWorld interface
A remote object“by-reference” that
implements the IHelloWorld interface
Implementing thesayHello methodImplementing thesayHello method
Server Code – Console Bootstrapping
using System;using System.Runtime.Remoting;using System.Runtime.Remoting.Channels;using System.Runtime.Remoting.Channels.Tcp;namespace RemotingHelloServer{
public class Server{
[STAThread]static void Main(string[] args){
//Create a TCP channelTcpChannel theChannel = new TcpChannel(8085)/* Register the channel so that clients can * connect to the server */ChannelServices.RegisterChannel(theChannel);
//Register the service on the channelRemotingConfiguration.ApplicationName = "HelloWorld App";RemotingConfiguration.RegisterWellKnownServiceType(
typeof(HelloWorld),"HelloWorld App",WellKnownObjectMode.SingleCall);
/*Start the server and keep it running so that clients * can connect to it. May be aborted by keypress */System.Console.WriteLine("Press Enter to end this server process");System.Console.Read();
}}
}
using System;using System.Runtime.Remoting;using System.Runtime.Remoting.Channels;using System.Runtime.Remoting.Channels.Tcp;namespace RemotingHelloServer{
public class Server{
[STAThread]static void Main(string[] args){
//Create a TCP channelTcpChannel theChannel = new TcpChannel(8085)/* Register the channel so that clients can * connect to the server */ChannelServices.RegisterChannel(theChannel);
//Register the service on the channelRemotingConfiguration.ApplicationName = "HelloWorld App";RemotingConfiguration.RegisterWellKnownServiceType(
typeof(HelloWorld),"HelloWorld App",WellKnownObjectMode.SingleCall);
/*Start the server and keep it running so that clients * can connect to it. May be aborted by keypress */System.Console.WriteLine("Press Enter to end this server process");System.Console.Read();
}}
}
Register the channelon port 8085
Register the channelon port 8085
Register theobject
Register theobject
Like in Java RMI (& CORBA) – we need some bootstrapping code – a server process Like in Java RMI (& CORBA) – we need some bootstrapping code – a server process
This may become a Windows NT service or a simple application, e.g. a console or Windows Form applicationThis may become a Windows NT service or a simple application, e.g. a console or Windows Form application
Client Code – Console Bootstrapping
… include all the Remoting stuffnamespace RemotingHelloClient{
public class Client{
[STAThread]static void Main(string[] args){
TcpChannel theChannel = new TcpChannel();ChannelServices.RegisterChannel(theChannel);
/* Activate the server object. Activation will bring * the server object to life, and create a proxy * stub class of the HelloWorld. In fact, as this is a * server-activated application, the call to the * server is NOT performed now, but instead waits until the * first request. It is thus the server who performs the * activation. This is the "Lazy-activation pattern" known * from e.g. CORBA */IHelloWorld helloWorld = (IHelloWorld) Activator.GetObject(
typeof(RemotingHelloServer.IHelloWorld),"tcp://localhost:8085/HelloWorld App");
System.Console.WriteLine("Please enter your name and press Enter");string name = System.Console.ReadLine();//Make the callstring greeting = helloWorld.sayHello(name);System.Console.WriteLine("We recieved from server: "+greeting);System.Console.WriteLine("Press Enter to end");System.Console.Read();
}}
}
… include all the Remoting stuffnamespace RemotingHelloClient{
public class Client{
[STAThread]static void Main(string[] args){
TcpChannel theChannel = new TcpChannel();ChannelServices.RegisterChannel(theChannel);
/* Activate the server object. Activation will bring * the server object to life, and create a proxy * stub class of the HelloWorld. In fact, as this is a * server-activated application, the call to the * server is NOT performed now, but instead waits until the * first request. It is thus the server who performs the * activation. This is the "Lazy-activation pattern" known * from e.g. CORBA */IHelloWorld helloWorld = (IHelloWorld) Activator.GetObject(
typeof(RemotingHelloServer.IHelloWorld),"tcp://localhost:8085/HelloWorld App");
System.Console.WriteLine("Please enter your name and press Enter");string name = System.Console.ReadLine();//Make the callstring greeting = helloWorld.sayHello(name);System.Console.WriteLine("We recieved from server: "+greeting);System.Console.WriteLine("Press Enter to end");System.Console.Read();
}}
}
Create ProxyCreate Proxy
Call via Proxy objectCall via Proxy object
Optional (may be done implicitly)Optional (may be done implicitly)
Configuration Strategi
• Alternative to Programmatic strategi:• Use a Server Configuration file (Listener.exe.config)
configuration> <system.runtime.remoting> <application> <service> <wellknown mode="Singleton" type="RemotableType, RemotableType" objectUri="RemotableType.rem" /> </service> <channels> <channel ref="http" port="8989"/> </channels> </application> </system.runtime.remoting></configuration>
Server Side Config Bootstrap
• Still need to implement: interface, MarshalByRef• But boostrapping is much simpler
using System;using System.Runtime.Remoting;
public class Listener{ public static void Main() { RemotingConfiguration.Configure("Listener.exe.config", false); Console.WriteLine("Listening for requests. Press enter to exit..."); Console.ReadLine(); } }
Client Configuration Strategi
• A Client Configuration file (Client.exe.config)
<configuration> <system.runtime.remoting> <application> <client> <wellknown type="RemotableType, RemotableType" url="http://localhost:8989/RemotableType.rem" /> </client> </application> </system.runtime.remoting></configuration>
Client Side Config Load + Proxy
• Still need to implement: interface, MarshalByRef• Generating dynamic proxy stub is simpler (VB.NET)
Imports SystemImports System.Runtime.Remoting
Public Shared Sub Main()
RemotingConfiguration.Configure(“Client.exe.config") Dim remoteObject As New RemotableType() Console.WriteLine(remoteObject.SayHello()) End Sub 'Main
Windows Communication Foundation (Kursorisk)
• Windows Vista => .NET Framework 3.0• Also for Windows XP and 2003 Server
• Unified Service-Oriented Programming Model
• Replaces / Suplements • .NET Remoting• DCOM• ASP.NET Web services• MSMQ (Queued Messaging) • .NET Enterprise Services
• Protocol Neutrality and Flexibility
http://msdn.microsoft.com/library/default.asp?url=/library/en-us/dnlong/html/wcfroadmap.asp http://msdn.microsoft.com/library/default.asp?url=/library/en-us/dnlong/html/wcfarch.asp http://msdn.microsoft.com/library/default.asp?url=/library/en-us/dnlong/html/wcfroadmap.asp http://msdn.microsoft.com/library/default.asp?url=/library/en-us/dnlong/html/wcfarch.asp
Defining the Contract
using System.ServiceModel;
//a WCF contract defined using an interface[ServiceContract]public interface IMath{ [OperationContract] int Add(int x, int y);}
using System.ServiceModel;
//a WCF contract defined using an interface[ServiceContract]public interface IMath{ [OperationContract] int Add(int x, int y);}
//the service class implements the interfacepublic class MathService : IMath{ public int Add(int x, int y) { return x + y; }}
//the service class implements the interfacepublic class MathService : IMath{ public int Add(int x, int y) { return x + y; }}
Implementing the Servicepublic class WCFServiceApp{ public void DefineEndpointProgrammable() { //create a service host for MathService ServiceHost sh = new ServiceHost(typeof(MathService));
//use the AddEndpoint helper method to //create the ServiceEndpoint and add it //to the ServiceDescription sh.AddServiceEndpoint( typeof(IMath), //contract type new WSHttpBinding(), //one of the built-in bindings "http://localhost/MathService/Ep1"); //the endpoint's address
//create and open the service runtime sh.Open();
}
public void DefineEndpointInConfig() { //create a service host for MathService ServiceHost sh = new ServiceHost (typeof(MathService));
//create and open the service runtime sh.Open();
}}
public class WCFServiceApp{ public void DefineEndpointProgrammable() { //create a service host for MathService ServiceHost sh = new ServiceHost(typeof(MathService));
//use the AddEndpoint helper method to //create the ServiceEndpoint and add it //to the ServiceDescription sh.AddServiceEndpoint( typeof(IMath), //contract type new WSHttpBinding(), //one of the built-in bindings "http://localhost/MathService/Ep1"); //the endpoint's address
//create and open the service runtime sh.Open();
}
public void DefineEndpointInConfig() { //create a service host for MathService ServiceHost sh = new ServiceHost (typeof(MathService));
//create and open the service runtime sh.Open();
}}
Create the Service EndpointProgrammatically
Create the Service EndpointProgrammatically
Create the Service Endpoint
Using a ConfigurationFile (see next slide)
Create the Service Endpoint
Using a ConfigurationFile (see next slide)
Configuration File
<!-- configuration file used by above code --><configuration xmlns="http://schemas.microsoft.com/.NetConfiguration/v2.0"> <system.serviceModel> <services> <!-- service element references the service type --> <service type="MathService"> <!-- endpoint element defines the ABC's of the endpoint --> <endpoint address="http://localhost/MathService/Ep1" binding="wsHttpBinding" contract="IMath"/> </service> </services> </system.serviceModel></configuration>
<!-- configuration file used by above code --><configuration xmlns="http://schemas.microsoft.com/.NetConfiguration/v2.0"> <system.serviceModel> <services> <!-- service element references the service type --> <service type="MathService"> <!-- endpoint element defines the ABC's of the endpoint --> <endpoint address="http://localhost/MathService/Ep1" binding="wsHttpBinding" contract="IMath"/> </service> </services> </system.serviceModel></configuration>
Implementing the Client Using Static Proxy
//this class is generated by svcutil.exe//from the service's metadata//generated config is not shown herepublic class MathProxy : IMath{ ...}
public class WCFClientApp{ public void SendMessageToEndpoint() { //this uses a proxy class that was //created by svcutil.exe from the service's metadata MathProxy proxy = new MathProxy();
int result = proxy.Add(35, 7); }
//this class is generated by svcutil.exe//from the service's metadata//generated config is not shown herepublic class MathProxy : IMath{ ...}
public class WCFClientApp{ public void SendMessageToEndpoint() { //this uses a proxy class that was //created by svcutil.exe from the service's metadata MathProxy proxy = new MathProxy();
int result = proxy.Add(35, 7); }
Implementing the Client Using Dynamic Proxy
public class WCFClientApp{
public void SendMessageToEndpointUsingChannel() { //this uses ChannelFactory to create the channel //you must specify the address, the binding and //the contract type (IMath) ChannelFactory<IMath> factory=new ChannelFactory<IMath>( new WSHttpBinding(), new EndpointAddress("http://localhost/MathService/Ep1")); IMath channel=factory.CreateChannel(); int result=channel.Add(35,7); factory.Close();
}
public class WCFClientApp{
public void SendMessageToEndpointUsingChannel() { //this uses ChannelFactory to create the channel //you must specify the address, the binding and //the contract type (IMath) ChannelFactory<IMath> factory=new ChannelFactory<IMath>( new WSHttpBinding(), new EndpointAddress("http://localhost/MathService/Ep1")); IMath channel=factory.CreateChannel(); int result=channel.Add(35,7); factory.Close();
}
Plenum Discussion
• Use 5 minutes in your groups:• Differences with CORBA?
• Strength over CORBA?
• Weaknesses compared to CORBA?
• Plenum: 5 minutes discussion of findings
Læringsmål Alignment
Når kurset er færdigt forventes den studerende at kunne:• Definere, beskrive og sammenligne forskellige typer af
objektorienterede middleware frameworks til apparater og computere, med primær fokus på CORBA og sekundært .NET Remoting teknologierne, herunder fordele og ulemper forbundet med de forskellige teknologier
• Definere og beskrive principper omkring transparens og heterogenitet i relation til middlewareteknologier
• Definere og beskrive gængse teorier, metoder og retningslinier indenfor det objektorienterede middleware paradigme og anvende disse til at designe effektive distribuerede systemer
• Designe og konstruere et distribueret system der gør brug af CORBA og .NET Remoting teknologierne med tilhørende værktøjssupport
I kan nu definere og beskrive
Grundlæggende .NETRemoting principper
I kan nu definere og beskrive
Grundlæggende .NETRemoting principper
Stubbe, dynamisk Proxy, ”IDL”,Retningslinier, transp., hetero.
manglende IDCl compiler, referencer
Stubbe, dynamisk Proxy, ”IDL”,Retningslinier, transp., hetero.
manglende IDCl compiler, referencer
Grundlæggende forståelse For hvad der skal til af CORBA
Teknologier, og værktøjer
Grundlæggende forståelse For hvad der skal til af CORBA
Teknologier, og værktøjer
MANGLER: praktisk arbejde med .NET Remoting -> se øvelser