Flashcards
Client-server and peer-to-peer
Cards in this deck (18)
- 1Client-server networkingOne or more computers (clients) connect to a powerful central computer (server)
The server may be distributed across multiple machines - 2Types of serverFile server - holds and manages data for clients
Print server - manages print requests
Web server - manages web access requests
Mail server - manages emails
Database server - manages databases - 3Client-server system structure1. Client sends a request to the server
2. Server processes the request and creates a response
3. The response is returned to the client (may be a confirmation if information is provided) - 4Client-server advantages1. Easy to manage - all files are stored centrally so access rights are only enforced on one machine
2. Backups are centralised - users don't need to back up their data
3. Data and other resources can easily be shared - 5Client-server disadvantages1. Expensive to install and manage
2. Professional staff are needed to maintain the servers and run the network
3. Rogue admins can easily steal data, making the network less secure
4. Server is a single point of failure - if it goes down, then the other machines can't access the required information - 6Peer-to-peer (P2P) networksNo central server - individual machines communicate with each other to find the information they need
- 7P2P advantages1. Cheap to set up
2. Enables users to share network peripherals
3. Easy to maintain
4. No single point of failure (network is self-healing)
5. E2EE easier - 8P2P disadvantages1. Easily used for online piracy as it is difficult to trace
2. Lack of centralisation means more work for users e.g. for backups - 9Cloud computingGrowing service-based industry
Provides access to software or files via the Internet
Client-server model
May store files or software (known as the Software As A Service or Saas model) - 10Client-side and server-side processingData may be processed by the client or the server (or both) in a client-server model
Commonly seen in web servers - a client sends HTTP requests to a server
Client-side - Data is processed on the client machine
Server-side - Data is processed on the server - 11Client-side processing tasks1. Initial data validation
2. Provide interactivity for webpages
3. Manipulate UI elements
4. Applystyles (e.g. CSS)
5. Reduce server load
6. Reduce web traffic - 12Server-side processing tasks1. Provide further validation e.g. to avoid MITM attacks
2. Query databases
3. Update server databases
4. Perform complex calculations
5. Encode data to readable HTML
6. Keep organisational data secure - 13Application Programming Interface (API)Set of protocols (rules) that govern how two applications should interact with one another
Sets out request and response format between the applications - 14Thin-client vs Thick-client system'Thickness' of client refers to the level of processing and storage that it does compared to the server
Thinnest-client option is a very basic machine with little processing power and no storage (a 'dumb terminal') - 15Thin-client advantages1. Easy to set up, maintain and add terminals
2. Software and updates can be installed on the server and automatically be distributed to each terminal - 16Thin-client disadvantages1. Reliant on the server, which becomes a single point of failure
2. Requires a very powerful, reliable and expensive server
3. Server demand and bandwidth increase - more costly
4. Maintaining network connections for portablle devices consumes more battery power than local processing - 17Thick-client advantages1. Robust and reliable (greater up-time)
2. Can operate without a continuous server connection - 18Thick-client disadvantages1. More expensive, higher-spec clients required
2. Installation of software required on each terminal separatly - network admin time increased
3. Integrity issues with distributed data
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- A level OCR A level Computer Science (Topic 5 - Networks and Web Technologies) Flashcards on Client-server and peer-to-peer, created by James Norman on 07/02/2020.
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- James Norman
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