TS/MP Pathsend and Server Programming Manual (G06.24+, H06.03+)

Glossary
NonStop TS/MP Pathsend and Server Programming Manual–132500
Glossary-20
Remote Duplicate Database Facility (RDF)
Remote Duplicate Database Facility (RDF). The Tandem software product that assists in
disaster recovery for OLTP production databases, monitors database updates audited by
the TMF subsystem on a primary system, and applies those updates to a copy of the
database on a remote system.
Remote Server Call (RSC). A Tandem software product that facilitates client/server
computing, allowing personal computer (PC) or workstation applications running under
Microsoft Windows software or the MS-DOS or OS/2 operating system to access
Pathway server classes and Guardian processes. Transactions are transmitted from the
PC or workstation application (the client) to a Pathway application running on a Tandem
NonStop system (the server) by means of a supported communications protocol, such as
NETBIOS, TCP/IP, or an asynchronous connection.
reply message. The part of an interprocess communication message that is formatted by a
server and returned to the original requester. The message contains the results of the
server’s work. See also request message.
reply translation header. A group of header fields that the Pathway translation server for the
NonStop TUXEDO system inserts at the beginning of each reply message it relays from
the application service to a SCREEN COBOL or Pathsend requester. This header
indicates whether the request was processed successfully and whether the reply contains
data returned by the application service. See also request translation header.
requester. A process or program that runs in the Guardian environment on a Tandem
NonStop system and requests services from a server process. For example, a SCREEN
COBOL program is a requester program that is interpreted by the terminal control
process (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.
request message. The part of an interprocess communication message that is formatted by a
requester and sent to a specific server. The message contains any data and instructions
needed by the server to perform its processing. See also reply message.
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