Compaq Reliable Transaction Router User Manual
Page 30
RTR Server Types
Figure 1–18 A Callout Server
Transaction
To
Partition A
TR
Callout
Server
Application
Server
BE
User Accounts Facility
LKG-11276-98WI
Authentication
RTR callout servers provide partition-independent processing for
authentication. For example, a callout server can enable checks
to be carried out on all requests in a given facility.
Callout servers run on backend or router nodes. They receive a
copy of every transaction either delivered to or passing through
the node.
Callout servers offer the following advantages:
•
The security check can run in parallel with the database
updates thus improving response times.
•
The security check can be run on the router hardware.
•
The security checking code is completely separated from
other application code.
Since this technique relies on backing out unauthorized
transactions, it is most suitable when only a small proportion of
transactions are expected to fail the security check, so as not to
have a performance impact.
1–20 Introduction