Cisco Cisco Unified Contact Center Enterprise 9.0(2) Maintenance Manual
In addition to configuration data, Peripheral Gateways, NICs, and the CallRouter itself all
produce historical data. The system components gather historical data and pass it to the
CallRouter, which then delivers it to the historical Logger and the central database. The historical
Logger passes the historical data on to an Historical Data Server (HDS) facility on an
Administration & Data Server.
produce historical data. The system components gather historical data and pass it to the
CallRouter, which then delivers it to the historical Logger and the central database. The historical
Logger passes the historical data on to an Historical Data Server (HDS) facility on an
Administration & Data Server.
The ability of the CallRouter to deliver data to the historical Logger and the central database is
not necessary for call routing. However, Unified ICM’s monitoring and reporting facilities
require both real-time data and historical data from the central database. Database fault tolerance
and data recovery, therefore, are extremely important to the reporting functions of Unified ICM
software.
not necessary for call routing. However, Unified ICM’s monitoring and reporting facilities
require both real-time data and historical data from the central database. Database fault tolerance
and data recovery, therefore, are extremely important to the reporting functions of Unified ICM
software.
Cisco Unified Intelligent Contact Management Database Recovery
Database recovery is the process of bringing an off-line database up to the same state as an
on-line database. In a database device failure (for example, in a disk failure), some manual
intervention is required to restore duplexed operation and bring the off-line database up to date.
The following scenarios describe what happens in a system failure, a disk failure, and a software
failure.
on-line database. In a database device failure (for example, in a disk failure), some manual
intervention is required to restore duplexed operation and bring the off-line database up to date.
The following scenarios describe what happens in a system failure, a disk failure, and a software
failure.
System Failure
When a single Logger, CallRouter, or Database Manager fails (for example, due to a power
outage), the associated central database will go off-line. The process of bringing the off-line
database back to full synchronization is completely automatic. If the Logger machine reboots,
SQL Server automatic recovery runs to ensure that the database is consistent and that all
transactions committed before the failure are recorded on disk.
outage), the associated central database will go off-line. The process of bringing the off-line
database back to full synchronization is completely automatic. If the Logger machine reboots,
SQL Server automatic recovery runs to ensure that the database is consistent and that all
transactions committed before the failure are recorded on disk.
Note: If the Logger machine does not reboot, SQL Server automatic recovery is not required.
After SQL Server automatic recovery is completed, the off-line Logger synchronizes its state
with the state of the on-line Logger. After the state transfer process takes place, both members
of the Logger pair can execute as a synchronized process pair.
with the state of the on-line Logger. After the state transfer process takes place, both members
of the Logger pair can execute as a synchronized process pair.
During the time that one database is off-line, configuration data might have been added to the
contents of the on-line database. If any configuration data changed while one database was
off-line, the configuration changes are applied to the database as part of the configuration
Logger’s state transfer process. This configuration update happens as part of the state transfer
before synchronized execution begins.
contents of the on-line database. If any configuration data changed while one database was
off-line, the configuration changes are applied to the database as part of the configuration
Logger’s state transfer process. This configuration update happens as part of the state transfer
before synchronized execution begins.
Any historical data that accumulated in the on-line database is recovered after synchronized
execution begins. Rather than attempting to recover the historical data immediately, the system
software first restores system fault tolerance (that is, duplexed database capability and
synchronized execution).
execution begins. Rather than attempting to recover the historical data immediately, the system
software first restores system fault tolerance (that is, duplexed database capability and
synchronized execution).
The system software recovers historical data from the on-line database using a special process
called Recovery. In Recovery, the historical Logger communicates with its counterpart on the
other side of the Central Controller and requests any historical data that was inserted during the
off-line period. The counterpart delivers the data over the private network that connects both
sides of a duplexed Central Controller.
called Recovery. In Recovery, the historical Logger communicates with its counterpart on the
other side of the Central Controller and requests any historical data that was inserted during the
off-line period. The counterpart delivers the data over the private network that connects both
sides of a duplexed Central Controller.
Administration Guide for Cisco Unified ICM/Contact Center Enterprise & Hosted Release 8.x
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Chapter 2: Fault Tolerance
Database Fault Tolerance