ClientServer Computing

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Client-Server Computing

• starting with the client side

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Access to information
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The Client/Server/Protocol Relationship
Client Initiates a Connection
Server Waits Responds to Incoming Connections
IP Addr 152.2.81.103
IP Addr 152.2.81.1
Server Application
Client Application
(A Program running on this machine)
(A Program running on this machine)
Application Protocol (HTTP)
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Client-Server Relationship
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the web as an example
Client Initiates a Connection
Server Waits Responds to Incoming Connections
Server Application
Client Application
The server finds the requested page and sends it
back to the client
(your web browser) sends a request for a URL to
a server
Application Protocol
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Server

• Definition
• A computer or device on a network that manages
  network resources.
• For example, a file server is a computer and
  storage device dedicated to storing files. Any
  user on the network can store files on the
  server.
• A print server is a computer that manages one or
  more printers, and a network server is a
  computer that manages network traffic.
• A database server is a computer system that
  processes database queries.
• Servers are often dedicated, meaning that they
  perform no other tasks besides their server
  tasks.
• On multiprocessing operating systems, however, a
  single computer can execute several programs at
  once.
• A server in this case could refer to the program
  that is managing resources rather than the entire
  computer.

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Servers

• Servers can be physical computers
• Servers can also be software applications
• One server (physical computer) can run many
  servers (software applications) at a time
• For example, Isis has several
• listproc
• web
• ftp
• mail
• address book

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Client

• Definition
• The client part of a client-server architecture.
• Typically, a client is an application that runs
  on a personal computer or workstation and relies
  on a server to perform some operations.
• For example, an e-mail client is an application
  that enables you to send and receive e-mail.

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Clients

• For any given application, there can be many
  clients
• People are more familiar with clients, since they
  interface with them directly
• Examples of clients are
• Netscape Navigator, Internet Explorer, Mozilla,
  Firefox
• WS-FTP, SSH, SecureCRT
• Any MSOffice application

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Looking at both sides
You need to know where you are
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Lets talk terminology

• Slides available at CNTLF information
• tools