Cutover is the process of reconfiguring an LMS application so that a replicating instance takes over as the current originating instance. This might be a planned activity, such as bringing down the originating instance for hardware maintenance, or it may be unplanned such as maintaining application availability when the originating instance or the network to the originating instance goes down.
Implementing and managing cutover is outside the scope of GT.M. FIS recommends you to adhere to the following rules while designing cutover:
Always ensure that there is only one originating instance at any given time where all database updates occur. If there is no originating instance, the LMS application is also not available.
Ensure that messages received from clients during a cutover are either rejected, so the clients timeout and retry, or are buffered and sent to the new originating instance.
Always configure a former originating instance to operate as a replicating instance whenever it resumes operations or comes back online after a crash.
Failing to follow these rules may result in the loss of database consistency between an originating instance and its replicating instances.