Availability Guide for Application Design

What Is Application Availability?
Availability Guide for Application Design—525637-004
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Why Is Availability Important?
Why Is Availability Important?
Demands for continuous services are increasing in almost all markets. To support
these demands, it is becoming increasingly important that computer applications are
always available. Service providers need to supply highly available applications in
order to:
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Gain a competitive edge
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Provide 24-hour operations
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Contain costs
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Reduce costs
•
Respond to life-threatening situations
Gain a Competitive Edge
Organizations can gain a competitive edge by meeting aggressive service objectives.
A bank, for example, needs continuously available applications if it is to provide its
customers with home banking and automated teller (ATM) services day and night to
equal or better the services provided by its competitors. Similarly, a stock market trader
must ensure high performance and low response times in support of a high volume of
transactions to meet the expectations of their customers and keep their trade.
24-Hour Operations
For many years, people in the developed world have expected certain services, such
as water, power, and telephone, to always be available. Today, the list of services that
operate 24 hours a day, seven days a week is increasing. This trend toward continuous
commerce exists because:
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More businesses are choosing to stay always open
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Customers need round-the-clock access to their money
•
Company operations are increasingly global
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Public expectations of round-the-clock service continue to increase
Open All Hours
Many businesses choose to stay open 24 hours a day. While the primary reason must
be to increase revenues, other factors also contribute to such policies. For example, a
restaurant might decide that it is more cost-effective to stay open than it is to leave its
lights on all night and post a security guard as deterrents to crime. In addition, the
public is changing its habits regarding when we work, eat, shop, and sleep. Retailers
and restaurants are responding to the changing behaviors of the population in order to
gain a competitive edge.
Round the Clock Access to Money
To enable customers to shop at any time, they must have constant access to their
money. Not only do automated tellers need to dispense cash at any time, but