Compaq Reliable Transaction Router - Manual (Page 38)

Flexibility and Growth
• User access patterns
• The volume of data
Since an RTR-based system can be built using multiple systems
at each functional layer, it easily lends itself to step-by-step
growth, avoiding unused capacity at each stage. With your
system still up and running, it is possible to:
• Create and delete concurrent server processes.
• Add or remove nodes (frontend, router or backend).
This means you do not need to provide spare capacity to allow
for growth.
RTR also allows parallel execution. This means that different
parts of a single transaction can be processed in parallel by
multiple servers.
RTR provides a comprehensive set of monitoring tools to help you
evaluate the volume of traffic passing through the system. This
can help you respond to unexpected load changes by altering the
system configuration dynamically.
Transaction Integrity
RTR greatly simplifies the design and coding of distributed
applications, because, with RTR, database actions can be
bundled together into transactions.
To ensure that your application deals with transactions correctly,
its transactions must be:
• Atomic
• Consistent
• Isolated
• Durable
These are the ACID properties of transactions. For more
detail on these properties, see the Reliable Transaction Router
Application Design Guide.
2–4 Architectural Concepts