Availability Guide for Change Management
Making Application Subsystem Changes Online
Availability Guide for Change Management–125506
4-3
Client/Server Computing and the Tandem
Application Environment
Client/Server Computing and the Tandem Application Environment
The Tandem application environment is a collection of processes and files designed to
facilitate the development and management of OLTP applications. The Tandem
transaction-processing services provide programs and an operating environment to help
you develop and run reliable, manageable, and cost-effective OLTP applications.
The transaction-processing environment consists of two types of programs: requester or
client programs and server programs.
In the client/server computing environment, programs are divided between a client
program, which resides on a personal computer (PC), Macintosh, or workstation, and
server programs, which reside on a host system such as a Tandem NonStop system.
Figure 4-1. The Tandem Application Environment
Note. Generally, the term “requester” refers to that part of an application that runs on a
Tandem NonStop system and makes requests of a server process. While a requester process
is conceptually the same as a client process, the term requester is retained for historical
reasons. The term “client” refers to the part of an application that runs on some other vendor’s
hardware—such as a PC, Macintosh, UNIX workstation, or mainframe computer system—and
makes requests of a server process. Client programs running on numerous hardware
platforms can make requests of server processes residing on Tandem’s massively parallel
server systems.
Middleware
Operating
System
CDT 003
NonStop TUXEDO PTP Pathway
NonStop SQL/MPNonStop TS/MP NonStop TM/MP
User Applications
TP
Monitor
Choices
Core
Services
003
Tandem NonStop Kernel
Guardian EnvironmentOpen System Services (OSS) Environment
Middleware products provide services to application programs while "hiding" the
underlying operating system platform.
TP monitor products provide transaction routing, resource allocation and
monitoring, APIs, development tools, and administrative tools.
The core services provide the Tandem fundamentals: Parallelism, Scalability,
Availability, and Manageability.