IBM AS/400e, Руководство пользователя

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AS/400 System Architecture: Underlying Strength of the AS/400e
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AS/400 System Architecture: Underlying Strength of the AS/400e
relational database, comprehensive security, communications with a broad range of diverse
systems, including Internet capabilities, and many more are already there in the operating
system. They are all fully integrated into OS/400 (AS/400e operating system). By “fully
integrated”, we mean fully tested, too. All components and prerequisites for running business
applications in the 2000s, work together and are fully tested together. OS/400 operates as a
single entity.
A customary machine does not have this approach to its operating system design. A
customary operating system, which does the basic system housekeeping, needs to have a
range of software products added to it before the environment is ready to support modern
business applications. Examples of this are: software for the relational database, support for
various communications environments, software for security, support for an interactive
environment, for multimedia, for availability and recoverability, and so on. On a customary
machine, many of these software modules are provided by third parties. A customer has to
assure that someone integrateed all these modules and performed the tests necessary to
verify that they all function together. When one of the software components has a new
release, a customer needs to again ensure that component is replaced, plus any other
software modules on which it depends. The modules need to be at compatible release levels.
Also, should a software malfunction occur, how do you establish precisely which modules are
causing it? Can you be certain that multiple third-party software vendors will agree with your
diagnosis when you blame their software?
There are none of these problems with OS/400. To achieve the functionality that is standard
in OS/400, a customer would need to integrate typically between 10 and 25 different modules
of software. OS/400 is installed with all these capabilities as standard. When software is
updated, a new release of OS/400 is made available. Customers do not have to install
individual system software components, nor do they have to check that new releases can
co-exist.
More details on OS/400 are provided in “Operating System/400, 5769-SS1” on page 451.
Hierarchy of Microprocessors
The following figure shows that the AS/400e system has a range of other processors, along
with its main system processor, dedicated to a particular input/output (I/O) device type. A
single large AS/400 configuration can have well over 200 processors.