Compaq Reliable Transaction Router - Manual (Page 45)

3
Reliability Features
Reliability in RTR is enhanced by the use of:
• Concurrent servers
• Standby servers
• Shadow servers
• Callout servers
• Router failover
Servers
Note that, conceptually, servers can be contrasted as follows:
• Concurrent servers handle similar transactions which access
the same data partition and run on the same node.
• Shadow servers handle the same transactions and run on
different nodes.
• Standby servers provide a node that can take over processing
on a data partition when the primary server or node fails.
• Callout servers run on backends or routers and receive all
messages within a facility so that authentication and logging
operations can be performed in parallel.
All servers are further described in the earlier section on RTR
Terminology.
Reliability Features 3–1