Patent ID: 7451215

Claim:
A method of redirection management, comprising: in response to an OPO create-event-subscription request from an OPC client, implementing interfaces associated with said OPO create-event-subscription request; creating a separate thread to handle said OPO create event-subscription request; using said separate thread to forward said OPC create-event-subscription request to a primary target OPO server for service; using said separate thread to forward said OPC create-event-subscription request to at least one additional target OPC server as inactive, said at least one additional target OPO server including a secondary target OPC server configured to backup said primary target OPO server; storing information related to said OPC create-event-subscription request, including state information; connecting to said primary target OPC server; connecting to an OPC server status change provider for said primary target OPC server; connecting to said at least one additional target OPC server; determining that said primary target OPO server supports OPO alarms and events; loading an alarms-and-events module providing at least one on-event request to said OPC client from said primary target OPC server; upon receiving an active-server-failed event from said OPC server status change provider for said primary target OPC server, performing a switchover to said secondary target OPC server; and notifying said alarms-and-events module of said switchover.