RTR Terminology
• Standby server
• Transactional shadowing
• RTR journal
• Partition
• Key range
• XA
RTR Application
An RTR application is user-written software that executes
within the con
fi
nes of several distributed
processes
. The RTR
application may perform user interface, business, and server
logic tasks and is written in response to some business need.
An RTR application can be written in one of the supported
languages, C, C++, or Java and includes calls to RTR. RTR
applications are composed of two kinds of actors, client
applications and server applications. An application process
is shown in diagrams as an oval, open for a client application
(see Figure 1–1),
fi
lled for a server application (see Figure 1–2).
Client
A
client
is always a
client application
, one that initiates
and demarcates a piece of work. In the context of RTR, a client
must run on a node de
fi
ned to have the frontend role. Clients
typically deal with presentation services, handling forms input,
screens, and so on. A client could connect to a browser running a
browser
applet
or be a webserver acting as a gateway. In other
contexts, a client can be a physical system, but in RTR and in
this document, physical clients are called frontends or nodes.
You can have more than one instance of a client on a node.
Figure 1–1 Client Symbol
Client
VM-0819A-AI
Introduction 1–5
