Transcript here in MS PowerPoint format

WMB-520: Web Technology
Web Server Setup
Meeting 1: Introduction to the Internet,
World Wide Web and Web Servers
Rutgers University Center for Applied
Computing Technology
Instructor: Christopher Uriarte
Web Technology – Web Server Setup : Chris Uriarte
Course Overview and Goals
• This course will teach you how to install,
configure, and administer a Web server that runs
on a Unix system and can be used to deliver
dynamic content.
• The course objectives will be achieved through
a combination of lectures, demonstrations, and
hands-on exercises.
Web Technology – Web Server Setup : Chris Uriarte
About Your Instructor…
• Chris Uriarte – [email protected]. Feel free to
contact me anytime via email.
• Homepage for this class linked from:
http://www.cju.com/classes
– Contains all slides, notes and misc. links and
resources.
Web Technology – Web Server Setup : Chris Uriarte
What This Course Is and Is Not
• The purpose of the course is to teach you the concepts behind
serving content on the web and how to run and administer web
server software on a UNIX system. This means you will be
learning how to use tools to deliver content for the World Wide
Web, not to create content.
• Rutgers offers other courses designed to teach you how to create
content for the World Wide Web (HTML design, Perl, etc.)
Web Technology – Web Server Setup : Chris Uriarte
Prerequisites
• Familiarity with a Web browser such as
Netscape or Internet Explorer.
• You MUST have user-level experience with
UNIX and must be familiar with the use of a
UNIX text editor like vi, emacs and pico
Web Technology – Web Server Setup : Chris Uriarte
Class Schedule
• Week 1: Introduction to the Internet, the World
Wide Web, and Web Servers
• Week 2: Installing and Configuring the Apache
Web Server
• Week 3: Extending Apache: Advanced Topics
• Week 4: More advanced configuration and Web
Security
• Note: classes 2-4 are hands-on classes.
Web Technology – Web Server Setup : Chris Uriarte
Course Resources
• Textbook: Apache: The Definitive Guide by
Laurie, Laurie and Denn (O’Reilly Press, 1999).
• User account on UNIX server
blender.rutgers.edu. (Remote access available
via SSH)
• Slides and resources on class hompage, linked
from http://www.cju.com/classes/
Web Technology – Web Server Setup : Chris Uriarte
How does the World Wide Web
Work?
• Works on a client/server model: The Web server
software is the server component, the Web
browser is the client component. Purpose of the
Web server is to provide documents to clients.
• Web servers, Web browsers, and the information
that is shared between them through the Hypertext
Transfer Protocol (HTTP) protocol make up the
World Wide Web.
Web Technology – Web Server Setup : Chris Uriarte
History of the World Wide Web
• Grew out of the Internet, a network of networks that
began in the early 1970’s and was used to support a
variety of services (including telnet, ftp, Usenet, email,
and gopher). Most of these services communicated via
via TCP/IP (Transmission Control Protocol/Internet
Protocol).
• In 1989, Tim Berners-Lee at CERN developed a new
system to simplify document distribution and to allow
documents to be linked together. Called the “World
Wide Web.”
Web Technology – Web Server Setup : Chris Uriarte
Web History, con’t.
• In 1993, the National Center for Supercomputing
Applications (NSCA) released to the public the
NCSA Web Server software and a GUI Web
browser, called Mosaic. Quickly became
popular.
• Mosaic became Netscape – first major web
browser distribution.
Web Technology – Web Server Setup : Chris Uriarte
The Web Today
• The Web has evolved greatly since it was first
implemented, but it’s overall architecture has
remained generally the same.
• Still fueled by three major components: A
network (typically the Internet, but can also
include local networks or Intranets), a client
component (a web browser) and a server
software component (what we’re going to
learn about in this class).
Web Technology – Web Server Setup : Chris Uriarte
Webmasters, Sys-Admins and
Developers, Oh My!
• There are a number of key roles that are
necessary to support a web infrastructure.
Providing end-to-end web services requires
knowledge about systems, network, software,
graphical design, programming and much more.
• There are many different
Web Technology – Web Server Setup : Chris Uriarte
Roles in the Web World:
• Web Designers – Create graphical elements and
determine layout of Website.
• Content Providers- Create and edit HTML
documents.
• Web Developers – Write web applications using
programming languages such as Java,
JavaScript, ASP, PHP and Perl other used to
deliver dynamic content.
Web Technology – Web Server Setup : Chris Uriarte
Roles in the Web World (con’t):
• System Administrators – Responsible for
maintaining the Web server software and often
the operating system and hardware where the
Web server is installed.
• Network Administrators – Responsible for the
design and maintanance of network components
used to deliver web content.
• For most organizations, these responsibilities
tend to be split over multiple job positions
except for very small and simple Web sites.
Web Technology – Web Server Setup : Chris Uriarte
Hosting A Website: The Planning
Phase
There are a number of key questions an organization or
individual must ask when planning to deploy a website:
–
–
–
–
–
How and where will you host it?
What kind of hardware will you use?
What kind of Operating System will the hardware run?
What Web server software will you use?
What domain name will your site use?
• Answers to above questions usually determined by
budget, staffing, and existing infrastructure of your
organization.
Web Technology – Web Server Setup : Chris Uriarte
Hosting Your Website: Options
• Use a Free Page Site – For personal use, limited space and
tools, typically adds advertisements. (examples: Yahoo, Tripod,
Xoom, etc.). Limitation on amount of traffic your site is
allowed. Generally not an option for business use.
• Personal Page Site – For personal use, usually included with an
ISP (about $20 per month), includes small amoung of disk
space, no or limited access to server-side technologies for
delivering dynamic content, generally uses your ISP’s Internet
domain name. Limitation on amount of traffic your site is
allowed. (Website URL usually looks something like:
http://www.yourisp.com/~yourusername). Might be an option
for very small businesses.
– Under both models, ISP owns and manages the server, network and web
server software. You simply provide the content.
Web Technology – Web Server Setup : Chris Uriarte
Hosting Your Website, con’t.
• Virtual Hosting – Most popular web hosting option todays.
Suitable for business or personal use. Using this model, an ISP
uses one machine to host many different websites (sometimes
called “shared hosting”). You can use your own Internet domain
name (http://www.yourdomain.com). These typically provide a
wide range of tools for building more complex Websites.
– ISP owns and manages the server, network and web server software. You
simply provide the content.
– Overall cost based on disk usage and website traffic, ranges from $20 to
several thousands of dollars a month. Now generally available through all
ISPs and specialized Hosting-only providers such as Highway
Technologies (http://www.hway.net) and YourDomainHost
(http://www.yourdomainhost.com)
Web Technology – Web Server Setup : Chris Uriarte
Hosting Your Website, con’t.
• Dedicated Server Services – For business use, ISP owns and the
hardware and network. Your organization typically has the option
of managing and configuring the server. You provide the
content. Your organization has exclusive access to the server.
– Price based on the type of server you require and the amount
of traffic your site uses.
• Co-Location Services (“co-lo”) – For business use - Your
organization owns and manages the hardware, software and
content. ISP provides you with space to place the server and the
network connectivity.
– Price based on the amount of space your servers require, the
power requirements of the servers and the amount of traffic.
Web Technology – Web Server Setup : Chris Uriarte
Hosting Your Website, con’t.
• Managing your Own Web Server Network
(“in-house” web hosting) – You provision,
configure and manage the network connection,
hardware, software and provide the content.
– Most flexible option – you have complete control.
– Cost can be very high or very low – depending on
the business need.
Web Technology – Web Server Setup : Chris Uriarte
Hosting Your Web Server: Do It
Yourself Networking Options
• For an Intranet Server– Need a LAN (local area
network). Does not require an Internet connection.
• For an Internet Server – Need a dedicated Internet
connection. Internet Connectivity Options:
– POTS (up to 56Kbps) – not practical for web use anymore.
– ISDN (128Kbps) – not practical for web use either (costly,
slow)
– Cable (512Kbps – 10Mbps)
– DSL (128kps – 1.54 Mbps+)
– T-1 (up to 1.54Mbps) – full, fractional, or burstable
– T-3 (up to 45 Mbps) – full, fractional, or burstable
Web Technology – Web Server Setup : Chris Uriarte
Finding an ISP
• Some ISPs specialize in web hosting and provide
all the service described earlier (shared hosting,
dedicated server, co-location, etc.).
• Other ISPs specialize only in commercial
Internet access (AOL, Earthlink, etc.). They
may provide free personal website space.
• Check The List – http://thelist.com, for a
comprehensive list ISPs and their services.
Web Technology – Web Server Setup : Chris Uriarte
Hosting Your Server: Hardware
Options
• There are a number of things to consider when choosing the
hardware platform for your website:
– Need to select a machine architecture (i.e Intel Compatible
PC, Sun, Macintosh) – Typically dictated by your Operating
System of choice
– Processor speed and number of processors.
– RAM and Disk Space.
– NIC card.
• Price can range from several hundred dollars to thousands of
dollars.
Web Technology – Web Server Setup : Chris Uriarte
Web Server Hardware Myths vs.
Realities
Myth
Reality
Web Technology – Web Server Setup : Chris Uriarte
Important Notes about Web
Server Hardware
• Web Servers need fast disk access and a lot of RAM to
handle high-volumes of traffic.
– Not unusual to see web servers with 1GB of RAM and
10,000RPM hard drives.
• Processor speed and performance becomes very important
when delivering dynamic content via custom web
application.
• High-end PCs can typically handle 100K+ website visits
per day.
Web Technology – Web Server Setup : Chris Uriarte
Hosting Your Server: Operating
System Options
• Commercial Versions of Unix (i.e. Solaris HP-UX,
AIX, MacOS X, IRIX).
• Free Versions of Unix (i.e. Linux, FreeBSD).
• Microsoft Windows (9x, NT, XP, Windows 2000).
• Windows vs. Unix – raises issues of easy of use,
stability, scalability, open source, and pricing.
UNIX platforms generally considered more
reliable, scaleable and cost-effective.
Web Technology – Web Server Setup : Chris Uriarte
Hosting Your Server: Web Server
Software Options
• The primary focus of this class will be
installing and configuration the web server
software – the software the turns an ordinary
computer into a computer that can host and
serve content on the World Wide Web.
• Web server software is often referred to as:
– The Web server
– The web daemon
– The “httpd”
Web Technology – Web Server Setup : Chris Uriarte
Hosting Your Server: Web Server
Software Options
• According to the Oct. 2002 Netcraft Web Server
Survey (http://www.netcraft.com), four Web
server software distributions support over 90%
of all Websites on the Internet:
–
–
–
–
Apache - 65%
Microsoft Internet Information Server - 25%
Zeus Web Server - 1.4%
iPlanet – 1.3%
Web Technology – Web Server Setup : Chris Uriarte
Web Server Software Options: Apache
• “The standard” for UNIX web servers..
• The most popular web server. Considered to be the
most secure, stable and robust server platform.
• Originally based on NCSA httpd code.
• Can be installed under most Unix variants and
Windows. Binary versions available for many
operating systems.
• Uses file-based configuration, although some GUI
tools are also available.
Web Technology – Web Server Setup : Chris Uriarte
Introduction to Apache, con’t.
• Unix versions very stable. Windows version less
mature, but becoming more stable. Apache 2.0 is
released.
• Very Fast and uses resources efficiently.
• Freely distributed source code. Can be modified for
commercial or non-commercial use.
• Price: Free. Developed by the Apache software
foundation.
• See http://www.apache.org for more information.
Web Technology – Web Server Setup : Chris Uriarte
Web Server Software Options:
SunOne/iPlanet/Netscape Server
• Now officially called the SunOne Web Server
• Originally developed as Netscape Server, then
distributed by partnership between Sun/Netscape, now
owned and supported by Sun.
• Server packages: iPlanet/Netscape Enterprise Server,
Netscape Fast-Track Server.
• Runs under Windows NT, Solaris, HP-UX, Digital
Unix, AIX, Linux.
Web Technology – Web Server Setup : Chris Uriarte
Netscape/SunOne Server, con’t.
•
•
•
•
•
Uses Web-based administration.
Can be resource intensive.
Lost major portion of market over last 5 years.
Price: $1495 per CPU
http://wwws.sun.com/software/products/web_srv
r/home_web_srvr.html for more information.
Web Technology – Web Server Setup : Chris Uriarte
Web Server Software Options:
Microsoft Internet Information
Server (IIS)
• Most popular for Win NT and 2000-based web
servers.
• Version 4 runs on Windows NT Server. IIS
version 5 runs on Windows 2000 Server (and XP,
but used for development purposes only).
• GUI-based administration. Web-based
administration available as well.
• May not scale well.
Web Technology – Web Server Setup : Chris Uriarte
Microsoft IIS, con’t.
• Increasing concerns over its security.
• Source code not available. Extendable through
Microsoft’s Internet Server API (ISAPI).
• Price: Free with NT Server 4.0 and Windows
2000 Server
• See
http://www.microsoft.com/windows2000/technol
ogies/web/default.asp for more information.
Web Technology – Web Server Setup : Chris Uriarte
How the Internet Works:
Networking Basics
• For a Web server to be useful needs to be
attached to a network.
• Minimum requirements for a computer
network – at least two computers that have
a media and a method of communicating.
• All Internet applications use TCP/IP
(Transmission Control Protocol/Internet
Protocol) for low-level communications.
Web Technology – Web Server Setup : Chris Uriarte
Networking Basics: TCP/IP
• TCP/IP is actually a combination of 2 protocols:
• A transport layer protocol called the
Transmission Control Protocol (TCP)
• A network protocol called the Internet Protocol
(IP)
Web Technology – Web Server Setup : Chris Uriarte
Networking Basics: IP Addresses
• TCP/IP uses IP address to identify different devices.
Every computer on the Internet must have a least one
unique IP address.
• IPv4: IP address are four 8-bit numbers separated by
dots: 165.230.30.68
– Usually divided in three parts:
– 165.230 is one of Rutgers’ networks – e.g. no one else has
addresses starting with 165.230
– 30 is the subnet portion of the address
– 68 is the particular node, or host portion of the address
• Division not necessarily on octet boundary.
Web Technology – Web Server Setup : Chris Uriarte
TCP/IP: Two Friends, Working
Together
• IP - An IP address represents a machine’s identity
on the internet and tells other machines how to get
to it – similar to your street address (e.g. 123 Main
Street, Anytown, USA).
• TCP is a mechanism used to ensure that anything
sent to a specific IP address makes it there in one
piece. – similar to the Post Office.
• Together, TCP/IP assures that anything sent to a
server on the Internet is delivered to the right
place in one complete piece.
Web Technology – Web Server Setup : Chris Uriarte
Networking Basics: IP Addresses
• IP addresses no longer being distributed by
classes – blocks are distributed to ISPs on an asneeded basis and must be justified.
• IP addresses are hard to come by. How do you
get them?
– Your ISP received an “address space” from the
ARIN (http://www.arin.org)
– You receive IP addresses from your ISP.
Web Technology – Web Server Setup : Chris Uriarte
Networking Basics: Tools
• Network interfaces need to be assigned IP
addresses.
• Interfaces can be configured using ifconfig
command on UNIX machines.
• Type ifconfig –a to view current configuration
settings.
• Additional tools for network monitoring: ping,
traceroute, tcpdump, netstat, arp, snoop.
Web Technology – Web Server Setup : Chris Uriarte
Networking Basics: DNS
• IP addresses are usually paired with more humanfriendly names The system that contains the IP
Address-to-Hostname pairing is called the
Domain Name System (DNS).
internet.rutgers.edu
Hostname
Organization Top-level domain
• Other top-level domains include .com, .gov,
.org, etc. There are also country-specific
domains like .uk, .ca, .jp, etc.
Web Technology – Web Server Setup : Chris Uriarte
Networking Basics: DNS, con’t.
• Domain name information is maintained through a
distributed database of host name/ IP address pairing.
• The Network Information Center (NIC) manages the
top-level domains and maintains a database of
registered name servers for all domain names.
• Host name assignments maintained through zone files
on primary and secondary DNS servers controlled by
the organization that owns the domain (or their ISP).
Web Technology – Web Server Setup : Chris Uriarte
Networking Basics: DNS, con’t.
• Network Solutions (previously the InterNic) registers
domain names – See http://www.networksolutions.com.
Other registrars include Register.com
• Costs range from $20 to $50 per year.
• ISP’s often offer domain name registration as part of
other packages (such as web hosting packages).
• Need to register a primary and secondary domain name
servers for your domain and arrange to have zone files
created on DNS servers. Your ISP will typically
configure this for you.
Web Technology – Web Server Setup : Chris Uriarte
DNS Overview: If Computers on the Internet Could Talk…
Web Technology – Web Server Setup : Chris Uriarte
Networking Basics: DNS Tools
• There are several tools for for monitoring DNS
information:
– whois – tells you the owner and primary DNS
servers associated with a domain (e.g. whois
yahoo.com). Also available via web browser at
www.networksolutions.com.
– nslookup and host – tell you IP address information
for a particular hostname on the internet (e.g.
nslookup www.yahoo.com or host www.rutgers.edu)
Web Technology – Web Server Setup : Chris Uriarte
DNS Exercise
• What are IP addresses of the DNS servers that
contain information about rutgers.edu?
• What are the IP address of:
– www.retaildecisions.com
– abusaday.admin.cju.com
– www.linux.org
Web Technology – Web Server Setup : Chris Uriarte
Networking Basics: Ports
• Servers tend to run a number of services. A single NIC can be
used to provide multiple services through ports.
• Network server software “listens” on specific ports. Clients
contact server by specifying an IP address and a connection port.
The port is the “identifier” that tells a server what application a
piece of network traffic is destined for.
• Common services and port numbers:
– smtp 25, ftp 21, telnet 23, http/web 80, https/ssl 443
– A list of services and ports is contained in the /etc/services
file on UNIX systems.
• Ports below 1024 are reserved for special system services and
can only be used by programs started by root (the system
administrator on a UNIX system).
Web Technology – Web Server Setup : Chris Uriarte
Uniform Resource Locator (URL)
• URL: a fancy way of saying “web site
address”
• Anatomy of a URL:
http://internet.rutgers.edu:80/ITI520/index.html
Protocol
Hostname
Port Number
Path To File
Web Technology – Web Server Setup : Chris Uriarte
Unix Tools and Commands
• File Editors: vi, emacs, pico
• File system navigation: cd
• File management: mv, rm, mkdir,rmdir, ls,
chmod, ln
• Archiving and compression: tar, gzip
• ***Process management: ps, kill
• Man pages available for all these
commands, e.g “man rmdir”
Web Technology – Web Server Setup : Chris Uriarte
UNIX Process Management
• UNIX Processes are managed using the ps and kill
commands
– ps is used to list processes running on the system
– kill is used to kill and restart processes running on the system
• Every time you start a new program (pico, vi, bash,
etc.) a process is created and you are the owner of that
process.
• Each process is assigned a unique Process ID (PID) on
the system
Web Technology – Web Server Setup : Chris Uriarte
Process Management Exercises
• You can type ps –aux to see all the processes
running on a system. This will list the process
owner, process ID (PID) and the command being
run.
• You can kill any PID, as long as you are the
owner of the process.
• ps –aux | grep username will show all the
processes your are currently running
Web Technology – Web Server Setup : Chris Uriarte
Process Management Exercises,
con’t.
• Open up a new UNIX terminal window and type
vi foo.txt. This will create a new process on the
system that you own.
• Open a second terminal window on the same
UNIX system. Locate the process ID for your
vi session and kill it. What happens?
Web Technology – Web Server Setup : Chris Uriarte
Reading for Next Week…
• As assigned in class…
Web Technology – Web Server Setup : Chris Uriarte