Computer Network and Distributed Client Server Client Server Architecture

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????????????????????????????????????Computer
Network and Distributed??????????? Client /
ServerClient / Server Architecture

• ??????????? ????????????

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Content

• Client / Server ???????
• ????????????? Client / Server
• ????? ????????????? Client / Server
• ????????? Client / Server
• ??????? Client / Server
• ????????? Client / Server Database

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Client / Server ???????

• Client / Server ??????????????????????????????????
  2 ???????
• Client ???? Software Module ???????????? Module
  ???? Server ?????????????????????? ?????????
  Request ?????????????????? Server 1
  ?????????????????
• Server ?? Module ?????????????? Request ???
  client ???? ????? Process ??????????????
  ?????????????????????? client
• ???????? Server ??????????????? Client
  ??????????????????????????? Server ???? ? ???

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Client / Server Computing

• ????????? Application ????????????????????????????
  ????(Modular approach to application design)
• ???????????????????????????????????? Share
• ????????????? Application ?????????????????
  hardware ????????(Hardware-independent to
  application Design)

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Modular approach

• ?????????????????????????? Application
  ????????????????????
• Presentation Logic ??????????? User
  ?????????????????????????
• Business Logic ???????????????????????? ????
  ????????????????? ?????????????
• Database Logic ????????????????????? ???????????
  ???????????????

Database Logic
Business Logic
Presentation Logic
Disk drive
Application
Terminal
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Client/Server Configuration
Reply
Database Logic
Business Logic
Presentation Logic
Request
Server Process with Database Logic
Client Process with Presentation Logic and
Business Logic
Disk drive
Terminal

• ?????? ???????????????? ? ?????????? Function
  Area ?????? ????????????????? Function Area ???? ?

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Software Sharing

• ???????????????? application ?????? Share Logic
  ??????
• ??????? ? ?????????????? Module ???????? ????
  Module ????? ????????????????? Application
  ??????? 1 ???
• ??????????????? Logic ???????? ???????
  Application ???????

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Hardware - Independent Approach

• Application ???????????????????????? Hardware
  ??????????
• ???????????????????? Stand Alone ???? Network

File/Print Server
Database Server
Clients
Bus. Logic
Pres. Logic
Request and Responses
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??????????

• ?????????????? Logic ????????????? Hardware
  ?????????????????????
• ??? Compiler ?????????????????? Program ???????
  Hardware ??????
• ??????? ??? Compile ??????????????????????
  Hardware , ??????? Platform ???? Compile Source
  ????
• ??? OOP ???? Hardware Independent ??????
• OLTP(On-Line Transaction Processing)
  ?????????????? Client/Server
• Process ?????????????????? Terminal -gt Host
• Process ??????????? Network
• Client / Server

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DBMS Client Server Environment
Operating System
DBMS
Application 1
Disk Device Driver
Disk1
Transaction Control Process
Disk2
Application 1
Disk3
Application 1
Database Logic
Business Logic
Presentation Logic
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????????? Client/Server
Database Logic
Business Logic
Presentation Logic
Server
Client
Database Server Model
Database Logic
Business Logic
Business Logic
Presentation Logic
Server
Client
Split Business Logic Model
Database Logic
Business Logic
Presentation Logic
Server
Client
Presentation Client Model
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????????????????? Client - Server

• ?????? remote procedure ?????????? message system
• Remote Procedure Call ????? Procedure Call ????
  Function Call
• Client ?????? input , output parameter
• Client ????? Procedure call ???? Network
• Request ????????????????????? RPC ?????
• Server ??????????????? Response Data
• RPC ???????????????
• Local RPC ???????????? Client

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Remote Procedure Call RPC

• 1.RPC thread ???????? client Process ????? RPC
  ???????????? stub
• 2.RPC thread ????????????????? network ??? Server
  
• 3.RPC thread ??????????????? call thread ??? ?
  RPC executes ?????????? execute ????? call thread
  ?????????????????? RPC thread
• 4.RPC thread ??????????????????? Network ???
  client
• 5.RPC Thread ??????? Application thread

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Message System

• ?????????????????????????????????
• Client ????????????????(Session)??? Server
• Message System Process ???????????? Address 3
  ???????
• Network Address , Node Address , Process Address
• Server ??????? SAP(Service Advertising Protocol)
• Client ?? Session ??? Server ???? Server
  ??????????????
• ????? Session ???????????????????????????????
  ?????? Process ???????

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SQL Server

• Client / Server Model ?????
• ???????????? SQL Server
• ???????????????????????????????
• ?????????????????????????????????????????? Server
• ?????????????? Data ???????????????????? DB
  Server ????? Share Load ???
• ??????????????????????????????????????????

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SQL Environment

• Client ?????????? User Interface , Business Logic
  , DBMS interface ??? Communication interface
• Server ???? Communication interface DBMS Software
  engine ??? Logic ????? Access ?????????

Business Logic
Database Driver A
Com. Interface
Database Server Vendor A
Database Driver B
Client Computer
Database Server Vendor B
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?????????????? Client/Server

• C/S ???????????????? process ???????????????
  ??????????? process ???????
• ???????? Logic ??? Server ???????????? ??????????
  Logic ?????????????????

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??????? client / server

• ???????????????
• Client / Server ???????????????????????
• Client ??????? Server ??? Server ???????????
  Client ??????????????
• ??????? Interface ??????? Client ??? Server ????
  Middleware
• middleware ??? ?????????????? Interface ???????
  Client Server ??????? Client ??? Server
  ??????????????????
• ORB(Object Request broker) ???????????????????????
  ?????? Client Server
• ODBC(Open Database Connectivity) ?????????
  ????????? client 1 ?????????????????????????
  Database ?????????????

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End.
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Thin or Fat

• Thin client and Fat Server
• ?????????????????????????? Server ????? client
  ???????????????????????????????
• Thin Server and Fat Client
• ?????????????????????????? client ????????????
  client ??????????????????