NonStop Systems Introduction

NonStop Systems Introduction—527825-001
6-1
6 The NonStop Kernel
Sections 3, 4, and 5 examined the NonStop application system environment and its
major components:
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Application development and integration
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Transaction control
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SQL/MX relational database management
•
TMF transaction management
You saw that this environment provides powerful support for your applications by
automating many functions that you would otherwise need to program explicitly. You
also observed that the NonStop application environment handles distributed
applications as easily as local applications.
This section and the next section examine the software and hardware foundation on
which the NonStop application environment is built:
•
This section describes the NonStop Kernel operating system and the Expand
network extension of the operating system.
•
Section 7, NonStop Server Architecture, explains the multiprocessor design of
NonStop servers and describes major hardware components of a NonStop server.
These two sections show that a NonStop system is designed as a single entity in which
hardware and software work together to provide fault tolerance, modular expandability,
efficient networking, and other important functions.
Application Services
Programs can access a variety of services provided by the NonStop Kernel. These
services make it possible to write applications that support the transaction processing
functions and perform other tasks necessary for process execution, such as
input/output and memory management. You access these services through one of the
two environments provided by HP.
HP provides two environments for developing and running applications on a NonStop
system: the Guardian environment and the Open System Services (OSS)
environment. Both environments provide commands, tools, and a set of procedure
calls (the application programming interface, or API) that enable an application
developer to access the services of the NonStop Kernel.
Figure 6-1 on page 6-2 shows the relationship of the two environments to the NonStop
Kernel and to each other. Note that the two environments are not themselves
operating systems but are simply layers that reside on top of and provide access to the
underlying operating system. Note also that processes in either environment can
access objects, such as files and other processes, in the other environment. And both
environments allow programmers to develop applications that support the
requirements of ZLE applications, such as fault tolerance, data integrity, and distributed