Grass Valley iControl V.6.02 - Manual (Page 478)

Backup and Redundancy
Auto-failovers
468
The Main network serves as the medium through which replication occurs between the Main
Application Server and the Backup, as well as being the primary path the Backup Application
Server uses to test the heartbeat of the Main. Only if the Backup does not receive the Main
Application Server’s heartbeat signal through the Main network will the Backup resort to the
Heartbeat network to listen for the Main Application Server’s heartbeat.
When a Redundancy Group is configured and online, any one of the following conditions can
cause a Main Application Server to automatically fail over to its Backup:
The iControl—Redundancy configuration page contains the following information about the
Redundancy Group and its Application Servers.
Note: When connecting your Application Servers to the networks, use the eth0
port to connect to the Main network. Use eth1 to connect to the Heartbeat network.
Condition Details
The Main Application Server loses network connectivity
on the Main network. The Main Application Server loses its network connection and is
unable to service its clients.
The Backup Application Server loses network
connectivity with the Main Application Server via both
the Main and the Heartbeat network (and the Backup
Application Server has connectivity on the Main
network). In this case, the Backup Application Server has no way of
knowing if the Main server has connectivity on the Main network.
It therefore takes over the Main’s responsibilities.
The Main Application Server stops responding or is too
overloaded to answer the Heartbeat request quickly
enough. In this case, pinging between the Backup and the Main
Application Servers is still possible but not quick enough.
The Main Application Server loses power. The Main Application Server shuts down because of a power loss
to that Application Server.
IMPORTANT: Make sure the Main Application Server’s resource usage is within
acceptable parameters
Prior to enabling the Auto-failover feature, the operator should make sure that
the Application resource usage on the Main Application Server (e.g. CPU usage,
RAM usage) is within acceptable limits so that it can respond to Heartbeat
requests from the Backup Application Server monitoring it.