Pathway Products Glossary

Glossary
Compaq NonStop™ Pathway Products Glossary—426762-001
Glossary-8
descriptor
descriptor. For each elementary data item, the SCREEN COBOL compiler builds a data
structure that describes the size, type, usage, and dependencies of the item. All of the
information that pertains to a given item makes up the descriptor for that item. For
example, the PICTURE specification is included in the descriptor. The descriptors are
passed to the TCP in the pseudocode and provide a dictionary of information for
interpreting and handling incoming data. When the MAP or SMAP compiler option is
used, the descriptors appear in the compiler map at the end of the listing.
diagnostic screen. A screen of information that is displayed to inform the terminal operator
of error conditions and termination status.
dialog. A multiple-message communication between a requester and a context-sensitive
server. A dialog is also called a conversation. See also context sensitivity
and context-
sensitive server.
direct server class. A server class in a Pathway/XM environment in which server processes
are accessed directly by a TCP or a LINKMON process, and which is managed by the
well-known named PATHMON process. When multiple PATHMON processes are
created within the Pathway/XM environment, such a server class operates as an
associative server under each additional PATHMON process. Direct server classes are
comparable to the server classes defined by the NonStop™ TS/MP product. See also
distributed server class
, replicated server class, and well-known named PATHMON
process.
disk process. The portion of the Compaq NonStop™ Kernel operating system that performs
read, write, and lock operations on disk volumes and creates TMF audit records. See
also file system
.
display attribute. A terminal display feature that is given a screen data name. The screen
data name can be associated with a predefined system name in the SPECIAL-NAMES
paragraph and thus be manipulated by a SCREEN COBOL program.
distributed data. Information (for example, customer names and addresses, inventory items,
and personnel records) that resides on more than one node in a network and can be
accessed by authorized users from any node in that network.
distributed processing. A type of processing environment in which resources are distributed
among CPUs within a single system or spread across a network of systems. A user on
any network node can, if properly authorized, access resources and database files
anywhere within the network.
distributed server class. A server class in a Pathway/XM environment in which server
processes are accessed through a link control service (LCS) process, with the assistance
of a process broker (PB) process, for automatic load balancing. Distributed server
classes can be suspended to allow online replacement. See also direct server class
,
replicated server class, link control service (LCS) process, and process broker (PB)
process.
Distributed Systems Management (DSM). A group of tools for managing a variety of
subsystems in a distributed processing environment.