Replication Frequency; Important Implementation Considerations - Cisco Servers User Manual

CiscoSecure Database Replication

Replication Frequency

Important Implementation Considerations

Cisco Secure ACS 3.0 for Windows 2000/NT Servers User Guide
8-10
The frequency with which your Cisco Secure ACS servers replicate can have
important implications for overall AAA performance. With shorter replication
frequencies, a secondary server is more up-to-date with the primary server. This
allows for a more current secondary Cisco Secure ACS server if the primary
Cisco Secure ACS server fails, including a more current CiscoSecure user
database.
There is a cost to having frequent replications. The greater the frequency of
replication, the higher the load on a multi-server Cisco Secure ACS architecture
and your network environment. Because Cisco Secure ACS transfers replicated
data more often, network traffic load is much higher. Also, processing load on the
synchronizing systems is increased. Replication consumes system resources, and
the more often replication is repeated, the greater the impact on the
Cisco Secure ACS server's AAA performance.
This issue is more apparent with large databases or frequently changing
databases. Database replication is a non-incremental, destructive backup. In other
words, it completely replaces the database and configuration on the secondary
Cisco Secure ACS server every time it is run. Therefore, if the database being
transferred is large, the amount of data being transferred can be substantial, and
the processing overhead can also be large.
Several important points bear consideration when implementing the CiscoSecure
Database Replication feature:
Cisco Secure ACS only supports database replication to other
•
Cisco Secure ACS servers. All Cisco Secure ACS servers participating in
CiscoSecure database replication must run the same version and patch level
of Cisco Secure ACS.
Only suitably configured, valid Cisco Secure ACS hosts can be secondary
•
Cisco Secure ACS servers. To add a secondary Cisco Secure ACS server,
configure the Cisco Secure ACS server in the AAA Servers table in the
Network Configuration section. When a Cisco Secure ACS server is added to
the AAA Servers table, it appears for selection as a secondary
Cisco Secure ACS server in the AAA Servers list under Replication Partners
on the CiscoSecure Database Replication page.
Chapter 8 Establishing Cisco Secure ACS System Configuration
78-13751-01, Version 3.0