Distributed Name Service (DNS) Management Programming Manual

DNS Subsystem Architecture
Introduction
46958 Tandem Computers Incorporated 1–3
Why Management
Programming for
DNS?
Sometimes, it is desirable to use a programmatic interface rather than an interactive
interface to manage a subsystem such as DNS. This is true for the following reasons:
A management application can handle routine object-management tasks, allowing
operators to perform work that requires judgement and creativity.
The information obtained through the programmatic interfaces can be used
directly by an application to determine how to proceed: to produce reports and so
forth.
A program can be constructed to accept any form of name for an object and then
use the DNS programmatic interface to resolve these names into underlying
subsystem object names.
An application that uses the programmatic interfaces to subsystems can automatically
perform tasks that once required the use of several different interactive interfaces. For
example, you could write a management application that adds new object names to a
DNS database when objects are added to a network, moves object names between
DNS databases, and deletes object names from a DNS database when objects are
removed from a network. Because objects are added, moved, and deleted from
systems and networks often, performing these repetitive operations programmatically
frees system operators to perform other tasks.
DNS Subsystem
Architecture
DNS consists of processes, configurations, and various files. Below is an overview of
the major elements of the DNS subsystem.
DNS Files Loaded by Install DNS is placed on your system by Install. During the REPSUBSYS phase, Install loads
the following files:
DNSCOM ($SYSTEM.SYSTEM.DNSCOM). Using DNSCOM commands, you can
create DNS databases, control the various DNS processes, and perform inquiries
and updates against DNS databases. These commands can be entered either
interactively from a terminal or programmatically from commands in disk files.
DNSMGR ($SYSTEM.SYSTEM.DNSMGR). DNSMGR is the executable object file
for the DNS name manager. A name manager is a management process through
which DNSCOM and user applications send SPI requests. All interaction between
programs (including DNSCOM) and DNS databases are performed by name
managers. Each DNS database has its own name manager process; hence, there
may be multiple name managers running simultaneously on a single system.
DNSEXP ($SYSTEM.SYSTEM.DNSEXP). DNSEXP is the executable file for the
DNS name exporter. All replication of name definitions from one node to another
are handled by name exporter processes. Each replicated DNS database has its
own name exporter process; consequently, there may be multiple name exporters
running simultaneously on a single system.
DNSHELP ($SYSTEM.SYSTEM.DNSHELP). DNSHELP is a data file used by
DNSCOM when responding to the HELP command and when constructing error
and warning messages.