TS/MP Pathsend and Server Programming Manual (H06.05+, J06.03+)

request translation
header
A group of header fields that must be included at the beginning of each request message a
SCREEN COBOL or Pathsend requester sends to the Pathway translation server for the NonStop
Tuxedo system. This header specifies the NonStop Tuxedo application service for which the
message is destined, the NonStop Tuxedo buffer types of the request and reply messages as seen
by the service, and options that modify the invocation of the service. The translation server removes
this header from the request message before sending it to the application service. See also reply
translation header.
request/response
model
A model for requester/server communication in which a requester passes a single request to a
server process and receives a single response. See also conversational model and
request/response server.
request/response
server
A server that provides request/response services. A service of type request/response is handled
like a procedure and has the following properties: it is executed until completion, it does not have
any dialog with the requester, and it sends back a return value to the requester. A request/response
server is analogous to a context-free Pathway server.
requester A process or program that runs in the Guardian environment on a NonStop system and requests
services from a server process. For example, a SCREEN COBOL program is a requester program
that is interpreted by the TCP, which provides link access to Pathway server classes. Another type
of requester program makes requests through Pathsend procedure calls; such a requester uses
the LINKMON process for link access to server classes. A third type of requester communicates
with server processes directly by calling the Guardian WRITEREAD procedure; this kind of requester
does not use server classes. A requester is a specific type of client. See also client, server, and
requester/server model.
requester/server
model
A model for application design that divides the tasks of data input, data manipulation, and data
output between two basic types of process: requesters and servers. A requester sends a request
to a server. The server takes the requested action and then replies to the requester. The requester
and server may reside on the same processor or on different processors. This model is used for
interprocess communication in the Guardian environment. See also requester and server.
reserved word A word that can be used only as a keyword.
resources The components of a computer system that work together to process transactions. Terminals,
workstations, CPUs, memory, I/O controllers, disk drives, processes, files, and applications are
examples of resources.
response time The amount of time it takes to receive a response from the system after initiating a request message
(for example, by pressing a function key).
retryable operation An operation that can be interrupted and repeated an indefinite number of times without affecting
the consistency of the database; for example, all read operations are retryable.
RISC See reduced instruction-set computing (RISC).
root directory An OSS directory associated with a process that the system uses for pathname resolution when
a pathname begins with a slash (/) character. See also OSS pathname.
RSC/MP See Remote Server Call (RSC).
scalability The ability to increase the size and processing power of an online transaction processing system
by adding processors and devices to a system, systems to a network, and so on, and to do so
easily and transparently without bringing systems down. Scalability is also sometimes called
expandability.
SCOBOLX The object file for the SCREEN COBOL compiler program. This name is given in a TACL command
to invoke the compiler. See also SCREEN COBOL.
screen A group of data fields that represent formatted data to be displayed on a terminal. A screen is
defined by a screen description entry in the Screen Section of a SCREEN COBOL program. There
are two types of screen: base screens and overlay screens. See also base screen, overlay screen,
and screen description entry.
SCREEN COBOL A procedural language developed by HP and based on COBOL that is used to define and control
screen displays on terminals and other input/output devices. SCREEN COBOL allows programmers
to write requester programs that communicate with operator terminals and intelligent input/output
devices, and that send data to server processes that manage application databases. SCREEN
210 Glossary