Introduction to TRANSFER Delivery System

TRANSFER and Tandem Software The TRANSFER Delivery System
1-10 109426—Introduction to TRANSFER Delivery System
TRANSFER and Tandem Software
By providing high-level package delivery and ways to distribute transactions over an
extended period of time, TRANSFER builds upon and enhances the capabilities of other
Tandem software. A TRANSFER application that runs in a network includes the
following software:
■ GUARDIAN 90, the Tandem operating system that runs on the NonStop series of
processors
■ EXPAND, an extension of GUARDIAN 90 that links geographically distributed
systems to create a network
■ PATHWAY, software that facilitates the development and control of online
transaction processing applications
■ Transaction Monitoring Facility (TMF), software that ensures database consistency
■ TRANSFER, software that provides package transport
In addition, Tandem provides gateways that allow Tandem users to exchange packages
of data with users and applications on other host systems.
GUARDIAN 90 and EXPAND—Distributed Processing
Tandem NonStop systems are built for distributed processing. An application is
structured as a set of communicating processes that can run in different processors, even
at different nodes in a network. The work of the application is thus distributed among
those processes.
GUARDIAN 90
The GUARDIAN 90 operating system prescribes a way for any two processes to
communicate by means of messages. One process makes requests and is therefore
called the requester. The other process receives requests, fulfills them, and replies; that
process is called the server. A process can be a requester with respect to one process
and a server with respect to another, as illustrated in Figure 1-4.
The GUARDIAN 90 file system is the interface between processes. The file system
allows a requester process to communicate with any other process or any device in the
network simply by making a file-system request that refers to the process or device by
name.