Distributed Applications

1

• Distributed Applications
• By
• Sam Nasr, MCP

www.ClevelandDotNet.info
2
Agenda

• Introduction
• COM
• Break
• .Net Remoting
• QA
• Survey

3

• COM

4
COM Services

• Accessed by Serviced Components
• Automatic Transaction Management
• JIT Activation
• Queued Components
• Security
• Loosely Coupled Events
• Object Pooling
• Utilizes System.EnterpriseServices.ServicedCompone
  nt Class

5
COM Transactions (ACID)

• Atomicity
• Consistency
• Isolation
• Durability

6
COM Security

• Role based security
• Declarative
• Programmatic
• Authentication
• Access Control
• Dim myIdentity As WindowsIdentity
  WindowsIdentity.GetCurrent()
• Dim myPrincipal as New WindowsPrincipal(myIdentity
  )
• If myPrincipal.IsInRole("Development") then
• 'Code to limit access
• End If
• myIdentity.IsAuthenitcated() checks if a user is
  authenticated
• myPrincipal.IsInRole() is used to check if a user
  is in a role.

7
JIT Activation

• Ensures client application has references to
  objects as long as needed.
• Object States
• Exists and activated
• Exists and not activated
• Non-existent

8
Service Related Attributes
9
COM Registration

• Types of Registration
• Manual
• Dynamic
• Programmatic
• RegScvs.exe for COM clients
• Vista Run windir\system32\comexp.msc

10
COM Resources

• Applying Attributes to Configure COM Services
• http//msdn2.microsoft.com/en-us/library/c11b9998(
  VS.71).aspx
• Integrating WCF Services with COM
• http//msdn2.microsoft.com/en-us/library/bb735856.
  aspx
• COM Services
• http//msdn2.microsoft.com/en-us/library/ms687015.
  aspx
• Roadmap for .Net Enterprise Services
• http//support.microsoft.com/kb/308672

11

• COM Demo

12

• Break

13

• .Net Remoting

14
What is .Net Remoting?

• Remoting is a technology that allows .NET
  applications to communicate.
• Same machine, across a network, or the Internet.
• Similar technologies COM, Direct TCP/IP socket
  connections, UDP diagrams, MSMQ messages, Web
  Services via http, SOAP

15
Remoting Terminology

• Marshalling the communication between a host
  and a client.
• Sink - an object that allows custom processing of
  messages during remote invocation.
• Channel an object that transports messages
  across remoting boundaries

16
Remoting Terminology

• Remotable object the object that can be
  marshaled across application domains.
• Formatter an object that is responsible for
  encoding/decoding and serializing data into
  messages.
• AppDomain an Application Domain, a .NET concept
  for a unit of isolation for an application.

17
System.Runtime.Remoting

• RemotingConfiguration class configures the
  remoting infrastructure.
• RemotingServices class provides methods for
  using and publishing remotable objects.
• ObjRef class generates a proxy, activates, and
  communicates with a remote object.

18
Distributed Application Development Technology

• In .NET, Enterprise Services are services in
  unmanaged code known as COM services.
• .NET Remoting is meant to replace DCOM.

19
.NET Remoting and Web Services

• .NET Remote objects can access remote resources
  without the overhead of SOAP based Web Services.
• .NET Remoting is easier to use than Javas RMI
  (Remote Method Invocation), but more difficult
  than creating a Web Service.
• The remoting system is flexible and easily
  customizable.
• Remoting system assumes no particular application
  model.
• Web services provide a standards-based, open
  communication medium.

20
QA