Compaq Reliable Transaction Router manual User Accounts Facility, 18 A Callout Server

RTR Server Types

Figure 1–18 A Callout Server

Callout

Server

TR

Transaction

User Accounts Facility

Application

Server

BE

To

Partition A

Authentication

LKG-11276-98WI

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.

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