6.6.5 Manually Forcing Failover
In redundant systems, it is common to require that a particular Server in the RedundantServerSet be taken out of the RedundantServerSet for a period of time. Some items that could cause this may include:
Certificate update
Security reconfiguration
Rebooting or restarting of the machine for
software updates and patches
installation of new software
Reconfiguration of the AddressSpace
The removal from the RedundantServerSet can be done through a complete shutdown or by setting the ServiceLevel of the Server to Maintenance sub-range. This can be done through a Server specific configuration tool or through the Method RequestServerStateChange on the ServerType. The Method is formally defined in OPC 10000-5.
This Method requires that the Client provide credentials with administrative rights on the Server.