1. WEB
SERVER
PRESENTED BY – SPRESENTED BY – SOURABH MULCHANDANI
4TH YEAR , 7TH SEM EC (B)
OURABH MULCHANDANI
4TH YEAPRESENTED BY – SOURABH MULCHANDANI
4TH YEAR , 7TH SEM EC (B)
R , 7TH SEM EC (B)
PRESENTED BY – DARANIYA NIRAV
- 090540107004
3TH YEAR , 5TH SEM CE
2. What is web server
A web server can be referred to as either the
hardware (the computer) or the software (the
computer application)
That helps to deliver content that can be accessed
through the Internet.
3. History of web
servers first web server.
The world's
In 1989 Tim Berners-Lee proposed to
his employer CERN (European
Organization for Nuclear Research) a
new project, which had the goal of
easing the exchange of information
between scientists by using a
hypertext system. As a result of the
implementation of this project, in 1990
Berners-Lee wrote two programs:
4. .
a browser called WorldWideWeb;
the world's first web server, later known
as CERN httpd, which ran on
NeXTSTEP.
5. Use Of Web Server
Host the websites.
Data storage.
To deliver web page on request of
client.
To deliver a HTML documents.
To deliver images , videos etc.
serving only a local network
monitoring and/or administrating
6. .
Ways To Request Content
Hypertext Transfer Protocol(HTTP)
File Transfer Protocol(FTP)
Internet Message Access
Protocol(IMAP)
7. Common features
Virtual hosting to serve many Web sites
using one IP address.
Large file support to be able to serve files
whose size is greater than 2 GB on 32 bit
OS.
Bandwidth throttling to limit the speed of
responses in order to not saturate the
network and to be able to serve more clients.
Server-side scripting to generate dynamic
Web pages, still keeping Web server and
Web site implementations separate from
each other.
10. . Example of an HTTP Request
.
from a Web browser
Command URL HTTP version
]- Request
GET http://www.kelley.indiana.edu/ardennis/home.htm HTTP/1.1
Date: Mon 06 Aug 2001 17:35:46 GMT Line
User-Agent: Mozilla/6.0 Web browser (this is Netscape)
]- Request
Referer: http://www.indiana.edu/~aisdept/faculty.htm Header
URL that contained the link to the requested URL
.
11. The Request
When you sit down at your computer and
point your browser to your favorite website
there are several transactions that take
place. First, your browser sends a request
to the server. This request header has a
defined format that is set by the W3C, the
organization that establishes the standards
for communicating through HTTP
(Hypertext Transfer Protocol) as well as
other internet standards. This header looks
similar to the following:
12. HTTP response from a Web server
HTTP version Status code Reason
.
.
HTTP/1.1 200 OK ]- Response Status
Date: Mon 06 Aug 2001 17:35:46 GMT ]- Date
Server: NCSA/1.3 ]- Web server Response
Location: http:// www.kelley.indiana.edu/adennis/home.htm ]- URL Header
Content-type: text/html ]- Type of file
<html>
<head>
<title>Allen R. Dennis</title>
</head>
<body> Response
<H2> Allen R. Dennis </H2> Body
<P>Welcome to the home page of Allen R. Dennis</P>
</body>
</html>
13. Developing a Response
After it has this information parsed, it
uses it to create a response header. First
it will verify that the file exists and the
user has permissions to view it. Next it
will build the response header, and then
send the header and the file (if
applicable) to the client IP. A example
header looks like this
15. Hosting a website : Self
hosting
Install a web server on a computer
Local access
◦ Using domain <localhost>
◦ or IP address 127.0.0.1
◦ Necessary for server-side programming
development
Global access
◦ Register a human-readable domain name
◦ Obtain IP address
Static: Costs more
Dynamic: Needs dynamic DNS system, e.g.
http://www.dyndns.com/
16. .
After instalation of Apache 6.0 in your
PC
You goto following path:
C:Program FilesApache Software
FoundationTomcat 6.0 web apps
In web apps folder paste your
websites contiants .
Close the window.
17. .
Now goto your web browser.
Write URL as…
http://localhost:8080/mywebsite/a.html
Now you can access your website
contain.
18. Load limits
A Web server (program) has defined
load limits, because it can handle only a
limited number of concurrent client
connections (usually between 2 and
80,000, by default between 500 and
1,000) per IP address (and TCP port)
and it can serve only a certain maximum
number of requests per second
depending on:
19. .
its own settings;
the HTTP request type;
content origin (static or dynamic);
the fact that the served content is or is
not cached;
the hardware and software limitations
of the OS where it is working;
When a Web server is near to or over
its limits, it becomes unresponsive.
20. Overload causes
At any time web servers can be
overloaded because of:
Too much legitimate web traffic.
Thousands or even millions of clients
connecting to the web site in a short
interval, e.g., Slashdot effect
XSS viruses can cause high traffic
because of millions of infected browsers
and/or Web servers;
21. .
Internet (network) slowdowns, so
that client requests are served more
slowly and the number of connections
increases so much that server limits
are reached;
22. Overload symptoms
TCP connections are refused or reset
(interrupted) before any content is sent
to clients;
in very rare cases, only partial contents
are sent (but this behavior may well be
considered a bug, even if it usually
depends on unavailable system
resources).
23. Anti-overload techniques
To partially overcome above load limits
and to prevent overload, most popular
Web sites use common techniques like:
managing network traffic, by using:
Firewalls to block unwanted traffic coming
from bad IP sources or having bad patterns;
HTTP traffic managers to drop, redirect or
rewrite requests having bad HTTP patterns;
24. .
deploying Web cache techniques
using different domain names to serve
different (static and dynamic) content
by separate Web servers, i.e.:
◦ http://images.example.com
◦ http://www.example.com
adding using more efficient computer
programs for Web servers, etc.;
more hardware resources (i.e. RAM,
disks) to each computer;
