Managing Sheer DNA Units
Cisco Systems, Inc. Page 71
The clustered N+m High Availability mechanism within the Sheer DNA
Fabric is designed to handle the failure of a Sheer DNA Unit. Sheer DNA
Unit availability is established in the Gateway, running a Protection Manager
process, which continuously monitors all the Sheer DNA Units in the
network. Once the Protection Manager detects a Sheer DNA Unit that is
malfunctioning, it automatically signals one of the m servers in its cluster to
load the configuration of the faulty unit (from the system Registry), taking
over all its managed Network Elements. The switchover to the redundant
standby Sheer DNA Unit does not result in any loss of information in the
system, as all of the information is auto-discovered from the network, and no
persistent storage synchronization is required. When a Sheer DNA Unit is
configured it can be designated as being an active or standby unit.
Note: The Sheer DNA system is usually configured with Sheer’s High
Availability mechanism enabled.
For more information about high availability, standby units, and defining a
redundant unit, refer to the Cisco Active Network Abstraction High
Availability User’s Guide.
5.2 Adding New Sheer DNA Units Sheer DNA Manage enables the user to add a Sheer DNA Unit to the Sheer
DNA Fabric. Sheer DNA Manage automatically registers the Sheer DNA
Unit in the registry and creates a transport uplink between the Sheer DNA
Unit and the Sheer DNA Gateway. The Sheer DNA Units are linked to the
Sheer DNA Gateway in a star topology.
In addition, the administrator can enable or disable high availability for a
Sheer DNA Unit. These settings enable the administrator to define to which
protection group a Sheer DNA Unit is assigned and whether it is enabled for
high availability.(For more information on high availability, refer to the
Cisco Active Network Abstraction High Availability User’s Guide.)
Note: By default all Sheer DNA Units in the Sheer DNA Fabric belong to
one big cluster, namely, the default-pg protection group.