Introduction to Data Management

Developing Applications With PATHWAY
6-6 15873 Tandem Computers Incorporated
SCUP is a utility program for managing libraries that contain the object code for
the screen programs produced by SCREEN COBOL or PATHAID. SCUP is
particularly useful when you want to manage multiple versions of object
programs.
System Management
Advantages
The modular construction of PATHWAY applications, plus a variety of other features,
makes them easy to configure, operate, and maintain. You can perform these tasks
through an interactive interface or request them from your own running programs, as
discussed later in this section.
You configure your PATHWAY applications to run under the PATHWAY operating
environment, which includes processes supplied by PATHWAY as well as processes
based on your own screen program and server code.
Convenient Expandability
PATHWAY applications are easy to expand. You can add terminals, communication
lines, databases, CPUs, new requesters, and new servers to a growing application
without changing any existing code. You can start additional copies of an application
on new CPUs, without any reprogramming. To handle varying workloads, you can
also add and delete copies of requesters and servers without shutting down the
application.
Efficient Use of Resources
On an individual basis, the terminals in an OLTP application are idle much of the
time. If a separate application process were required for running each terminal, many
idle processes would exist in main memory, waiting for activation by their users. But
because a single TCP can handle many terminals, PATHWAY conserves the use of
main memory on your system.
Dynamic Load Balancing
PATHWAY helps you balance your processing workload. If peak activity on a
particular server affects response time, PATHWAY can create additional copies of the
server dynamically and then delete them automatically when activity slows down
again. If the number of terminals or transactions increases to the point where they
affect response time, PATHWAY lets you add additional copies of requesters. If peak
activity on a particular processor affects response time, PATHWAY allows you to add
more requesters and servers to less active processors. You can perform all of these
operations, and others, without shutting down your PATHWAY system.