Pathway/iTS System Management Manual (G06.24+)

Introduction to Pathway/iTS System Management
HP NonStop Pathway/iTS System Management Manual—426748-002
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Pathway/iTS Objects and Processes
Pathway/iTS Objects and Processes
The following elements of a Pathway environment are provided by the Pathway/iTS
product. Information about defining and managing these items is given in this manual.
TCP Objects
A terminal control process (TCP) interprets and executes screen program instructions
for each input-output (I/O) device or process the TCP is configured to handle. The TCP
coordinates communication between screen programs and their I/O devices or
processes and, with the help of the PATHMON process, establishes links between the
screen programs and server processes. The TCP also performs these tasks:
•
Verifies and stores terminal context data and terminal control logic
•
Gathers statistics about TERM objects, the server processes, and itself
•
Reports operating errors and status information to the PATHMON process
•
Provides integrity across failure situations
Because it is a multithreaded process, a TCP can concurrently manage many user
terminals and execute many screen programs. To accomplish these tasks, the TCP
runs its TERM or PROGRAM objects as threads, interleaving the concurrent
processing of requests originating from many I/O devices or processes. This
multithreading allows the TCP to handle complex groups of operations for many users
at the same time.
The TCP manages the operation of multiple I/O devices by maintaining separate
screen program code and data areas for each device under its control. In addition to
managing operation of terminals, the TCP supports card readers, local printers, and
bar-code readers when they are attached to terminals.
To support browser-based web clients, Pathway/iTS also provides a prewritten screen
program called the gateway. When you configure a TCP to interpret and execute the
gateway program, the gateway threads work with the router process to manage links
for web clients. Each TERM object under this TCP is associated with a socket, and
there is one client connection per TERM object. Each gateway requester thread is
associated with one router process, whose connections it handles. The TERM objects
under this TCP are all associated with a particular router process and application.
TERM and PROGRAM Objects
TERM objects represent tasks controlling the input-output devices and processes that
allow users to interact directly or programmatically with a Pathway application. Each
task runs as a thread in the TCP; the TCP can handle many such threads concurrently.
There are two types of these objects: configured TERM objects and temporary TERM
objects.
Configured TERM objects are those you define and add to the PATHMON
configuration file. Temporary TERM objects are created for you (and automatically