Publishing a web site
requires space on a web server - a computer
that is permanently connected to the Internet.
Web page files are uploaded to a web server
using FTP - file transfer protocol. There
are millions of web servers connected to
Internet. Each machine is identified by
its IP address - a series of numbers that
is unique to that machine.
When selecting a web
server there are two things that need to
be considered: disk space and bandwidth.
Most hosting packages provide more disk
space that is needed for the average web
site.
How web sites are published
to the Internet
The vast majority of
web sites are hosted on commercial servers
where space is rented on a machine that
hosts multiple web sites. So, can a business
buy its own web server and connect it to
the Internet to host its own web site in
house? The answer is "no" for 99% of web
sites because the cost of doing so would
be so high as to make it a ludicrously
uneconomical option. The single largest
cost of this approach would be the price
that would have to be paid for a permanently
on leased line into the Internet.
That is, of course, after
one has met the cost of a qualified technician
to look after and maintain the server.
Web server configuration and maintenance
requires high levels of technical knowledge
and expertise. Commercial web sites have
to be available and working 24 hours a
day, seven days a week. Technical support
much therefore be always available to deal
with any problems arising with the server.
There are various kinds
of web servers
The majority of small
web sites are hosted on virtual servers.
Larger web sites might need to be run from
a dedicated server which is co-located
in a server farm. In such cases, the customer
either purchases their own server and delivers
it to the hosting company or purchases
one from the hosting company. This machine
is then connected to the hosting company's
Internet connection. This approach reduces
the cost of having a dedicated line into
the Internet.
Bandwidth is the amount
of web traffic going to and from the server
over a period of time. Some hosting providers
set limits to bandwidth and/or charge extra
if those limits are exceeded. Some hosting
providers make a point of offering unlimited
bandwidth, or at least appearing to do
so.
Web servers are similar
to ordinary computers, except that, for
most of them, the operating system is UNIX
or LINEX rather than Windows.
Unix or Linex based
servers tend to cost less than Windows
based servers, simply because the operating
and web software is either free or very
cheap. Some authorities claim that Windows
web servers are less secure and more
unstable than their Unix/Linex based
equivalents. Such views are often hotly
debated.
The software that runs
on web servers
The software that deals
with requests for web pages and the multitude
of other procedures connected with the
management of web sites is called "Apache"
(see the Apache
web site.)
Web servers that handle
financial transactions, such as those involved
in online shopping and sales, should be
able to provide a secure server.
The servers that handle
the delivery of web pages to the Internet
very often also handle email traffic. This
is because domain names are usually pointed
to one IP address and therefore that machine
has to handle both web and email traffic.
This is certainly the case with incoming
email. Emails that are sent out can often
be routed via the servers of the company
providing the Internet connection - the
Internet Service Provider or ISP.
Facilities provided by
web site hosting
Web servers can provide
more than just space for web sites. It
is common for hosting services to offer
additional options, such as FrontPage extensions
for handling web sites built with FrontPage
web design software. Some hosting services
provide scripts for handling such things
as forms on web pages. This might require
the hosting to have a CGI-BIN in which
such scripts can be stored: a special folder
which holds scripts and has special permissions
that allow the scripts to be executed.
A quality hosting service
will also provide a statistics package
so that the number of visitors to a web
site can be counted and analysed. The Apache
server automatically records each call
for a web page or file. The data is stored
in "log files" and these files can be analysed
to provide valuable information about the
number of times a site is visited, which
IP addresses have called for those pages,
the rate of visits per day or month and
much more besides.
A good
hosting will also provide the ability
to handle databases. Such facilities are
necessary where a web site must provide
visitors with a large volume of data. High
volume data is stored in a system called
SQL or MYSQL (the latter is pronounced
"my sequel".)
Managing and controlling
web servers
Good quality web hosting
services provide their customers with control
panels. These are web pages that allow
users to manage their web space and do
such things as create and delete email
addresses. Such administrative facilities
often come in the form of proprietary systems
such as DirectAdmin, cPanel or Plesk. These
facilities provide a user friendly front
end to the commands that are required to
manage the web server. Originally, all
such commands had to be issued manually
from a keyboard and required the operator
to know Unix commands.
Another feature of good
web servers is that they are regular backed
up, so that, if anything goes wrong with
the server, the original web sites can
be restored from the security backup files.
Check out technical terms concerned with
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