A mainframe computer is
a big computer. IBM builds mainframe computers. Today, a mainframe refers to
IBM's System Z servers. Many large corporations like banks, insurance
companies, travel and retail sector, telecom companies process data on a
mainframe. Today, thousands of people around the globe book flights, do wire
transfers, make credit-card purchases. These transactions are processed in a
snap by a mainframe.
Mainframe RAS features:
Reliability is the ability of computer hardware or
software to consistently perform according to its specifications.
Mathematically, reliability measure is the mean time to failure(MTTF). Availability is
the ratio of the up time of a system to the total time. Serviceability is
an expression of the ease with which a system can be maintained or repaired.
The reliability, availability and serviceability features
are in the System Z's DNA. System Z is designed to provide an availability of
99.999% (five 9s). The "Z" in System
Z's brand-name stands for zero down-time. System Z
servers have reported an MTTF of 40 years. Organizations run their
mission-critical applications on mainframe to provide 24/7 availability.
System Z
processors use an instruction retry mechanism.
Every instruction that executes successfully on the System Z processor is check
pointed, the processor state is saved. If an error is detected, a recovery
sequence commences. The processor is fenced off. The processor state is
refreshed from the last checkpoint and the instruction is retried. Like having
spare tires on a truck, System Z offers chip redundancy. If one
processor fails, System Z can dynamically switch to a
spare without losing a beat! Thousands of error checkers(parity, residue, illegal
state, hardware redundancy compares and so on) are embedded on the chip.
Are
Mainframe computers good at everything?
Well, not
quite. Mainframes are not good at number-crunching or don't
do scientific calculations. A Mainframe is not a Super-computer. You would n’t
use a Mainframe computer to calculate the value of Pi, up to 1000-decimal
Places. Mainframe-Computers are not meant for speed. They are n’t fast,
rather they can process humungous data reliably. You can't play games like
Counter-Strike or Half-Life on a Mainframe.
Mainframe
computers don’t have a beautiful user-interface like the PC
at your home. You would n’t find a desktop wallpaper or icons on a mainframe
computer.
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Below are the Tutorials to learn IBM Mainframes Technologies.
This website is under construction....
