Databases Reference
In-Depth Information
that is specifically not connected to the Internet. In the Internet database envi-
ronment, the general public potentially has access (planned or unplanned access
by hackers) to the company's company's databases. The public responses to the
applications that involve the Internet are often unpredictable, meaning that the
load on the system and access to the databases can change rapidly. The environ-
ment requires constant monitoring and management, with administrators having
to react quickly when the situation changes.
12.3.1 Managing Performance Issues
Most Web users experience widely different performance levels when interact-
ing with the Web. Sometimes, the performance varies on visits to the same
Web site.
Response time,
the elapsed time from pressing the Enter key or
clicking on a “Go” icon to having the Web server's response as a new Web page
fully displayed on your monitor, can vary greatly. Response, or perceived
response (how quickly the Web server seems to respond), can be critical. Com-
petition for customers continues to increase with ever more companies offer-
ing ever more services. A consumer's lack of patience with poor performance
at one Web site can easily mean that the customer will leave for a competitor's
site. The complexity of the Internet and Web environment means that there
are many potential reasons for poor performance. Performance varies depend-
ing on whether your connection to the Internet is through a dial-up (56K)
modem or a broadband connection, the level of hardware at your Internet ser-
vice provider, traffic levels with which you're competing, Web server response
speed, and so forth.
From the point of view of the Web site, a major factor is the amount of traf-
fic coming in from the Internet. Internet traffic to a Web site, the number of
people or companies trying to access it simultaneously, can vary greatly because
of a variety of factors such as the following:
▲
The time of day (which must be considered on a worldwide basis).
▲
The season of the year (e.g., the Christmas shopping season).
▲
The changing popularity of a Web site.
▲
A major new product release (or product rumors).
▲
A major event (with an overwhelming spike in traffic possibly overload-
ing the server).
These spikes (some huge) in Internet traffic require predictive capacity plan-
ning. Companies want to be able to maintain reasonable response times during
spikes without spending large amounts of money to buy a lot of extra computer
equipment that will sit idle much or most of the time. Accomplishing this takes
planning and significant expertise.
