5. 6. 7. The Web Flashcards Preview

COMP18112 - Distributed Systems > 5. 6. 7. The Web > Flashcards

Flashcards in 5. 6. 7. The Web Deck (9)
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1
Q

What is the Web?

A

A DS for linking together hypertext documents.

A client server architecture with pages hosted by web servers and viewed by client web servers

2
Q

What is the protocol for communication between client and server?

A

HTTP, pages written using hyper text markup language

3
Q

Pros and cons of client server architecture?

A

Pro: behaviour easy to understand
Con: server is a single point of failure and performance bottleneck

4
Q

What makes the web reliable?

A

Statelessness. Every request is independent of every other.

5
Q

What is a URI

A

Universal Resource Identifier.

A URI that specifies locations is URL (http://www.example.com). One that specifies name is URN (book code)

6
Q

What are the eight different methods of HTTP?

A

GET- request named resource
HEAD- metadata about a resource
POST- client sends data to server
PUT- put information from client to web server
DELETE- delete a resource
TRACE- used for debugging
OPTIONS- which commands a server will respond to
CONNECT- begins communication with resource

7
Q

What happens when a user decides on a page to view?

A

Client connects to the appropriate server- Look at protocol, Look at DN, find IP address
Fetches the content- GET
Renders it nicely so the user can see
Disconnects

8
Q

How can a web application appear to hold state?

A

GET and POST- client sends info about itself to the server so it can be recognised next time
Cookies- request the client to remember something and pass it back to the server next time

9
Q

Key Properties of the web?

A
Single point to point communication
Client/server architecture
Stateless communication
Common port 80
Every transaction is independent of every other as far as protocol is concerned.