WebFund 2014W Lecture 6 - Revision history

Soma at 21:02, 26 January 2014

2014-01-26T21:02:53Z

← Older revision		Revision as of 21:02, 26 January 2014
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	Video from the lecture given on January 24, 2014 is available:		Video from the lecture given on January 24, 2014 is available:
			* [http://www.screencast.com/t/8wuWC7k35rE small at screencast.com] (flash/mp4)
			* [http://www.screencast.com/t/8jhcxWGsl large at screencast.com] (flash/mp4)
			* [http://dl.cuol.ca/capture/Anil.Somayaji/COMP_2406_2014W_Lecture_6_-_20140124_144406_27.mp4 original at CUOL] (mp4)
			* [http://homeostasis.scs.carleton.ca/~soma/webfund-2014w/lectures/comp2406-2013f-lec06-24Jan2014.mp4 original at homeostasis] (mp4)

	==Notes==		==Notes==

Soma at 21:00, 26 January 2014

2014-01-26T21:00:25Z

← Older revision		Revision as of 21:00, 26 January 2014
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			==Video==

			Video from the lecture given on January 24, 2014 is available:


			==Notes==
	• Client-server		• Client-server
	o Key distinction: Which ports they communicate on		o Key distinction: Which ports they communicate on

IlyA: Lecture 6 Notes

2014-01-24T22:40:09Z

Lecture 6 Notes

New page

• Client-server
o Key distinction: Which ports they communicate on
o Web server means "I have a port listening on port 80"
• TCP/IP
o Port number: Identifies programs, 16 bit
• DNS
o Translating host-names to IP address
o When typing in an address, browser needs to do a DNS lookup to translate it to an IP address
• HTTP
o Modern browsers assume everything starts with "http://"
• HTML

• URL: Uniform Resource Locator
o Components
 Name of the server you wish to contact
 Resource you're requesting
• Server: A "box" to serve and deal with requests
• Internet: A network of other local networks, connecting them to each other
• Packets: 1500 bytes, switched networks, how computers send information to each other over a network
o Packet loss: When you're on a connection that loses too many packets, TCP cannot provide the illusion that you're on a continuous data stream
• IP address: source and destination both have one
o Can ping computers to find out their IP addresses and find the IP address of a server serving a webpage
o Identifies the computer to talk to
• When you're writing a web server, you're just writing a program that's running on a different port, and talking through TCP/IP
• express: a framework
o Difference between framework and middleware: Middleware is code that you can use; a framework is a way to organize your code, that may use middleware
• require: importing code from a directory to save time, instead of writing it yourself
o Looks for the file that was input as a parameter
• var user refers to ./routers/user, but it's not used so it doesn't do anything
• Web servers have infinite loops, in order to wait for events to come in so that they may handle it