NonStop Systems Introduction for H-Series RVUs

Glossary
NonStop Systems Introduction for H-Series RVUs—540083-001
Glossary-8
Open System Services (OSS).
Open System Services (OSS). An open system environment available for interactive or
programmatic use with the NonStop operating system. Processes that run in the OSS
environment use the OSS application program interface. Interactive users of the OSS
environment use the OSS shell for their command interpreter. The OSS API and shell
are similar to those provided by the UNIX operating system.
ORB. See object request broker (ORB).
OSS. See Open System Services (OSS).
parallelism. The ability to distribute applications, databases, and processing power over
multiple processors in a NonStop system and over multiple NonStop systems in an
Expand network.
Pathway environment. A run-time environment consisting of NonStop transaction-
processing products for the Guardian operating environment.
portability. The ability to use, or migrate, application software, system software, and data
across different computing platforms from multiple vendors.
power-fail delay. See ride-through power backup.
power-fail interrupt . A processor function that interrupts the current instruction stream,
when a power failure occurs, in order to invoke a power-fail interrupt handler. This
interrupt handler provides an orderly shutdown sequence that preserves the existing
state of processor memory for subsequent resumption of operation when power is
restored. See also ride-through power backup.
primary process. The currently active process of a process pair managed by the NonStop
operating system. See also backup process and process pair.
process. (1) A unique execution of a program in the Guardian environment. (2) An entity in
the Open System Services environment consisting of an address space, a single
thread of control that executes within that address space, and the system resources
required by that thread of control.
process management. The managing of online transaction processing applications on
multiple NonStop systems. Process management functions include configuration and
initialization of processes, monitoring and stopping of processes, and recovery of failed
processes.
process pair. A fault-tolerant arrangement of processes in the Guardian environment
whereby two processes (usually in separate processors) share the same name and
execute identical code. One process functions as the primary process and the other
functions as the backup process. The two processes are synchronized through
checkpoint messages sent from the primary to the backup process. If the primary
process fails, the backup process becomes the primary and continues the application
work from the last valid checkpoint message.