A Cold Failover mode is where the Client can only connect to one Server at a time. When the Client loses connectivity with the Active Server it will attempt a connection to the redundant Server(s) which may or may not be available. In this situation the Client may need to wait for the redundant Server to become available and then create Subscriptions and MonitoredItems and activate publishing. The Client shall cache any information that is required related to the list of available Servers in the Redundant Server Set. Figure 29 illustrate the action a Client would take if it is talking to a Server using Cold Failover mode.


Figure 29 – Cold Failover

Note: There may be a loss of data from the time the connection to the Active Server is interrupted until the time the Client gets Publish Responses from the backup Server.