Each phase of a switch as shown by the steps in Figure 8 is needed to ensure a complete (planned or unplanned) switch. The phases are described below.
Step 1: Switchover - This phase moves production system users to the backup system. You will need two switchover processes, one for a planned switch and one for an unplanned switch. For detailed information about the events in this phase, see Events and status: Starting a planned switch to a backup system and Events and status: Starting an unplanned switch to a backup system.
Step 2: Synchronization - This phase replicates changes made on the backup system, while the backup system acted as the temporary production system. In a basic MIMIX environment, you would perform this phase after the production system is up and running again. For detailed information about the events in this phase, see Events and status: Starting the switch synchronization.
Step 3: Switchback - This phase switches users to the production system after all changes have been replicated to the production system by the synchronization process. For detailed information about the events in this phase, see Events and status: Returning to the production system.
In the following figure, the term backup system refers to the original backup system where the MIMIX Model Switch Framework programs are stored. The term production system refers to the Production system definition (PRDSYSDFN) parameter from the CRTSWTFWK and CHGSWTFWK commands.
Figure 8. MIMIX switch cycle