Switching over to a standby system is a vital aspect of maintaining business continuity during emergencies or planned changes. Understanding switchover options will empower you to choose the most suitable method tailored to your specific needs and ensure a smooth transition to the standby system.
1. DEFINED_SWITCH: The DEFINED_SWITCH option involves a planned switch of the production and standby systems during normal operation mode. The production database files on the primary system are mirrored to the standby database on the secondary system. After a successful DEFINED_SWITCH, the production database resides on the secondary system, while the standby database becomes the primary system. This switch cannot be executed in emergency situations and requires access to the production system.
2. LOSSLESS: The lossless switchover option ensures that all data changes on the primary system, including committed transactions to the production database, are present in the newly activated database on the secondary system. It is used when a DEFINED_SWITCH is not possible. Before initiating the lossless switch, all online log files need to be copied to a designated folder on the secondary system.
3. END_OF_LOGS: The END_OF_LOGS switchover option proves invaluable in situations where the production system is inaccessible or completely destroyed - such as during a database center outage or a loss of connectivity. By loading all available log files onto the standby system, it can be transformed into the new production system. This approach allows for swift recovery and continuity of operations, even without direct access to the original production system.
4. POINT_IN_TIME: POINT_IN_TIME switchover enables you to restore your database to a specific timestamp, providing the flexibility to choose an earlier state for the switch. It allows you to rollback to a desired point in time, which can be useful for recovering from data corruption or logical errors. After the switch, an initial-copy job is required to resume data mirroring.
With our Libelle BusinessShadow® solution for disaster recovery and high availability, you can mirror databases and other application systems with a time delay. Our patented and dynamically adjustable time funnel temporarily stores the change logs before they are mirrored to the standby-system. Switching over to this system in the event of an error or even maintenance can thus be carried out with impressive speed and without any fuss.
Switching over to a standby system is a crucial aspect of maintaining business continuity during emergencies or planned changes. By understanding the END_OF_LOGS, POINT_IN_TIME, DEFINED_SWITCH, and LOSSLESS switchover options, you can choose the most appropriate method based on your specific requirements. Whether you prioritize zero data loss, the ability to roll back to a specific point in time, or planned transitions, these options provide flexibility and resilience for seamless system transitions.