Message-Passing Communication Analyzer By Poonam Bijlani CSE 775- Distributed Objects Prof. Jim Fawcett

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Message-Passing Communication AnalyzerByPoonam
BijlaniCSE 775- Distributed ObjectsProf. Jim
Fawcett
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Project Overview

• The message passing Communication Analyzer is
  implemented as a two way communication subsystem
  using .NET Remoting.
• Xml Messages are passed between the client and
  server.
• The system can be configured in any of the
  following activation modes
• Singleton one object for all clients
• Single Call one object created for each call to
  the server
• Client Activated one object for each client
• Configuration files are used to establish any of
  the activation modes

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Project Overview..contd

• Sponsors are implemented to prevent the
  communication object from timing out if it is
  implemented as singleton or client activated.
• Average time to service a message is found by
  sending a stream of continuous messages between
  client and server.

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Context Diagram
Communication using .Net Remoting
Xml Messages
Messages
I/P
Marshal ByRef
User Interface
Input and
Client
Proxy
Server
Output
O/P
Object
Errors
Errors
Errors
Errors
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GUI
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Client Classes
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Server Classes
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Configuration files, Controls and Interfaces

• Configuration Files used to set the remoting
  infrastructure between client and server. Also
  used to set the activation model.
• Controls
• XML Generator Generates XML messages of required
  size
• HiRes Timer Calculates the time, in
  microseconds, to send and receive a message from
  the client to the server and back.
• Interfaces
• ILease and ISponsor Used for Lifetime management
  of Client Activated and Singleton Objects

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Sponsors

• .NET Remoting uses a lease-based form of
  distributed garbage collection to manage the
  lifetime of remote objects.
• MyClientSponsor Class on the client side is used
  to renew the lease for Singleton and Client
  Activated objects after they have expired
• The sponsor implements the ISponsor interface and
  registers the Sponsor using the Register( )
  method of the ILease interface.
• The Lease Manager calls the renewal( ) method to
  renew the lifetime of the objects. I have used a
  time span of 20 seconds which means that the
  Lease Manager renews the objects lease time by 20
  seconds each time it calls the renewal ( )
  method.

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Client- Thread and Queues

• Queues
• Send Queue
• Receive Queue
• Threads
• Main Thread- Handles GUI and queues request for
  server
• Communication Thread Takes care of communication
• Receive Thread De-queues messages posted by the
  communication thread and populates GUI

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Server Threads and Queues

• Queues
• Send Queue
• Receive Queue
• Blocking Queues implemented on both client and
  server to avoid wasting CPU cycles
• Threads
• Communication Thread- Takes care of communication
• Worker Thread- Responsible for serving the
  Clients requests

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Communication Subsystem
SERVER
Communication
Communication
CLIENT
Thread
Thread
RECIEVE Q
Child Thread
SEND Q
dequeues,
processes request
enqueues
Main Thread
response
XML MESSAGES
RECIEVE Q
Main Thread
enqueues server
Receiver
requests/
Thread
notifications
SEND Q
Singleton/
SingleCall/
ClientActivated
Remotable
Object
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Client Activity Diagram
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Server Activity
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Event Trace Diagram
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Singleton 1 Client
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Single Call 1 Client
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Client Activated 1 Client
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Comparative Graph- 1 Client
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Singleton Multi Client
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Single Call Multi Client
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Client Activated Multi Client
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Comparative Graph- Multi Client
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Uses

• Calculate performance of distributed applications
  using messages up to 100Kb eg. Chat Applications
• Can be modified by using PassByReference file
  transfer to measure the performance of
  distributed file systems, eg. FTP
• Can be used to compare speeds of different
  networks eg. Dial-up, Broadband etc.

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Conclusion

• A message passing communication analyzer was
  successfully built and implemented using .NET
  remoting
• Further, it was operated in three modes
  Singleton, Single Call and Client Activated
• A HiRes Timer was used to analyze the performance
  of the system with increasing message sizes for a
  single client and up to 8 clients for a single
  message size.
• Tests indicated that distributed applications
  where state preservation is not required, a
  client activated object should be preferred over
  Single Call.
• Further choice of activation mode depends on the
  specific requirements of the application under
  consideration.

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Thank You
Questions?