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Mainframe concepts
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Who uses mainframes and why do they do it?
Mainframe concepts
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So, who uses mainframes? Just about everyone has used amainframe computer at
one point or another. If you ever used an automatedteller machine (ATM) to
interact with your bank account, you used a mainframe.
Today, mainframe computers play a central role in the daily operationsof most
of the world's largest corporations. While other forms of computingare used
extensively in business in various capacities, the mainframe occupiesa coveted
place in today's e-business environment. In banking,finance, health care,
insurance, utilities, government, and a multitude ofother public and private
enterprises, the mainframe computer continues tobe the foundation of modern
business.
Until the mid-1990s, mainframes provided the only acceptable meansof handling
the data processing requirements of a large business. These requirementswere
then (and are often now) based on running large and complex programs,such as
payroll and general ledger processing.
The mainframe owes much of its popularity and longevity to its
inherentreliability and stability, a result of careful and steady technological
advancesthat have been made since the introduction of the System/360™ in 1964.
No other computerarchitecture can claim as much continuous, evolutionary
improvement, whilemaintaining compatibility with previous releases.
Because of these design strengths, the mainframe is often used by IT
organizationsto host the most important, mission-critical applications.
Theseapplications typically include customer order processing, financial
transactions,production and inventory control, payroll, as well as many other
types ofwork.
One common impression of a mainframe's user interface is the 80x24-character
"greenscreen" terminal, named for the old cathode ray tube (CRT) monitors
fromyears ago that glowed green. In reality, mainframe interfaces today look
muchthe same as those for personal computers or UNIX® systems. When a business
applicationis accessed through a Web browser, there is often a mainframe
computer performingcrucial functions behind the scenes.
Many of today's busiest Web sites store their production databases on
amainframe host. New mainframe hardware and software products are ideal forWeb
transactions because they are designed to allow huge numbers of usersand
applications to rapidly and simultaneously access the same data
withoutinterfering with each other. This security, scalability, and reliability
iscritical to the efficient and secure operation of contemporary
informationprocessing.
Corporations use mainframes for applications that depend on scalabilityand
reliability. For example, a banking institution could use a mainframeto host
the database of its customer accounts, for which transactions canbe submitted
from any of thousands of ATM locations worldwide.
Businesses today rely on the mainframe to:
- Perform large-scale transaction processing (thousands of transactionsper
second)
- Support thousands of users and application programs concurrently
accessingnumerous resources
- Manage terabytes of information in databases
- Handle large-bandwidth communication
The roads of the information superhighway often lead to a mainframe.
- Mainframe strengths: Reliability, availability, and serviceability
The reliability, availability, and serviceability (or "RAS")of a computer
system have always been important factors in data processing.When we say that a
particular computer system "exhibits RAS characteristics," wemean that its
design places a high priority on the system remaining in serviceat all times.
Ideally, RAS is a central design feature of all aspects of acomputer system,
including the applications.
- Mainframe strengths: Security
One of a firm's most valuable resources is its data: Customer lists,accounting
data, employee information, and so on. This critical data needsto be securely
managed and controlled, and, simultaneously, made availableto those users
authorized to see it. The mainframe computer has extensivecapabilities to
simultaneously share, but still protect, the firm's data amongmultiple users.
- Mainframe strengths: Scalability
It has been said that the only constant is change. Nowhere is thatstatement
more true than in the IT industry. In business, positive resultscan often
trigger a growth in IT infrastructure to cope with increased demand.The degree
to which the IT organization can add capacity without disruptionto normal
business processes or without incurring excessive overhead
(nonproductiveprocessing) is largely determined by the scalability of the
particularcomputing platform.
- Mainframe strength: Continuing compatibility
Mainframe customers tend to have a very large financial investmentin their
applications and data. Some applications have been developed andrefined over
decades. Some applications were written many years ago, whileothers may have
been written "yesterday." The ability of an applicationto work in the system or
its ability to work with other devices or programsis called compatibility.
Parent topic: The value of the mainframe today |
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On Saturday, May 11, 2019, 7:54:17 PM EDT, Phil Smith III <[email protected]>
wrote:
You know, I'm as big a fan of the mainframe as anyone. I've used mainframes
for at least 45 of my 58 years on this planet, have made my living off them for
almost 40 of those, and continue to do so.
But the articles Bill Johnson is citing as proof that the mainframe is so
superior to other platforms are seriously weak, if read with a critical eye.
For those of us in the mainframe part of the industry, failing to recognize
that the mainframe is in trouble is beyond folly-it's hastening its demise.
Every year, more customers migrate away because they can, or at least think
they can. The real value of the mainframe today is in the business logic
implemented in billions of lines of COBOL and assembler and PL/I and the rest.
Reimplementing that from the ground up is what fails every time, whether
spectacularly (as in, it flat-out doesn't work and has to be scrapped) or not
(with "only" significant loss of function and/or bugs that the folks on the
ground must work through with great cost and pain).
We as mainframe fans need to keep our eyes on that ball, and use that extremely
compelling argument against migration, not wave our hands and say "It's
gooderT!" and expect that to somehow prevail against the evidence.
.phsiii
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