If in the future the main machine fails and the backup needs to become
primary, follow these steps:
Ensure that the main machine stops replicating, if it is still
accessible, to avoid further confusion. Go to System
Replication Settings / Targets on the main machine and
remove all target(s), then hit Update at the bottom to apply
this. If the main machine is inacessible, simply make sure it stays
down.
Make the backup machine live for searches as appropriate
(e.g. switch your organization's proxy or web site to refer to it,
change its IP/hostname, etc.). We now refer to this as the new main
machine.
Turn off receiving replication on the new main machine: under
System → System Setup → System
Wide Settings, set Allow Receiving to N.
Replace/restore the new backup (old main) machine, and configure
as a backup per above.
