Transcript Net Remoting - as. N.Angelowa

.Net Remoting
Distributed Computing under
.Net

In .Net, there are three levels of access to
distributed computing machinery:

Low Level:
 System.Net.Sockets

Intermediate Level
 System.Runtime.InteropSerives

Access COM objects and Win32 API
 System.Runtime.Remoting



Access channels and CLR activation
Channels based on TCP or HTTP over TCP
High Level
.Net Remoting
2
Distributed Computing under
.Net

System.Net.Sockets
Provides low-level access to socket objects
 You create listeners and send and receive just
like we did in
CSE691 – Software Modeling and Analysis


System.Runtime.Remoting
Provides access at a medium level of
abstraction.
 You create channels and proxies and do
RPCs on remote objects

.Net Remoting
3
Remoting .Net Libraries

System.Runtime.Remoting.Activation


System.Runtime.Remoting.Channels


Uses binary transmission over sockets
System.Runtime.Remoting.Contexts


Uses SOAP protocol to communicate with remote
objects
System.Runtime.Remoting.Channels.TCP


Sets up channel sinks and sources for remote objects
System.Runtime.Remoting.Channels.HTTP


Activate remote objects
Set threading and security contexts for remoting
System.Runtime.Remoting.Messaging

.Net Remoting
Classes to handle message
passing through
message sinks
4
Distributed Computing under
.Net

System.Web.Services
Servers are hosted under IIS
 Use HTTP-GET and HTTP-POST or higher
level SOAP


Simple Object Access Protocol (SOAP)
Wraps XML message in SOAP envelope
(XML tags)
 SOAP messages are interpreted by IIS and
ASP
 Typically use standard and/or custom COM

.Net Remoting
5
Web Related .Net Libraries

System.Web

System.Web.Hosting
 Communicate
with IIS and ISAPI run-time
System.Web.Mail
 System.Web.Security

 cookies,

web authentication, Passport
System.Web.Services – close ties to ASP.NET
 System.Web.Services.Description
 System.Web.Services.Discovery
 System.Web.Services.Protocol
.Net Remoting
SOAP requests
– raw HTTP and
6
Remoting Architecture
.Net Remoting uses
System.Runtime.Remoting
 It is built on processing that supports:


Channels
 A channel
is a socket-based communication
mechanism that can use either basic TCP protocol
or the higher HTTP layer.

Activation
 Activation
is basically the same process that the
CLR uses to create local objects.

.Net Remoting
You just have to tell
the CLR what object you want.
7
Remoting Architecture
Application Domain
Application Domain
server object
client Object
proxy for
Remote-able
Object
Remote-able
Object
channel
channel
CLR Thread
CLR Thread
.Net Remoting
8
Basic .Net Remoting – Remote
Object

First create a remote-able object:
Design an object to be invoked remotely,
derived from MarshalByRef
 Implement the class as a C# library – this
creates a dll.
 Any objects that you need to pass to that
object need to be serializable.

 The
basic types like ints and strings already are
serializable.
 Your class objects need to have the [Serializable]
.Net Remoting
attribute and contain
only serializable data
members.
9
Remoting Architecture
Application Domain
Application Domain
server object
client Object
proxy for
Remote-able
Object
Remote-able
Object
channel
channel
CLR Thread
CLR Thread
.Net Remoting
10
Basic .Net Remoting – the
Server

Create a server:
Design a C# class, using a C# Console
Application, or Empty Project in which you will
create a WinForm.
 In a member function – main will work:

 Create
a TcpServerChannel
 Register the Channel with ChannelServices
 Register the type of object clients want to use
remotely by calling
RegisterWellKnownServiceType

Then, block the main thread.
.Net Remoting
11
Remoting Architecture
Application Domain
Application Domain
server object
client Object
proxy for
Remote-able
Object
Remote-able
Object
channel
channel
CLR Thread
CLR Thread
.Net Remoting
12
Basic .Net Remoting – the
Client

Create a client:
Design a C# class, using a C# Console
Application, or Empty Project in which you will
create a WinForm.
 In a member function – main will work:

 Create
a TcpServerChannel
 Register the Channel with ChannelServices

In a member function – main will work:
 Create
a proxy to access the remote component.
You do this by calling Activator.GetObject(…) and
casting the result to the type of the remote object.

Note that both client
and server need the assembly for
.Net Remoting
the remote-able object.
13
Remoting Architecture
Application Domain
Application Domain
server object
client Object
proxy for
Remote-able
Object
Remote-able
Object
channel
channel
CLR Thread
CLR Thread
.Net Remoting
14
Architecture for Project #3

The previous slides described a classic
client/server configuration.

For Project #3 we need something a little
more sophisticated.
 In
a classic client/server only the client initiates
communication.
 In Project #3 you will have to have the “server”
make notifications back on the “client”.
I would create a reply function that works just
like the server, described earlier, except that
the thread does not block after setting up the
channel, but instead returns.
 I would create a request function that works

.Net Remoting
15