- Test fast-start failover without impacting the production database
- Determine when a failover or other interaction would have occurred during
normal production processing
- Discover what circumstances would cause an automatic failover to occur
- Easier justify using Fast-Start Failover s to reduce the recovery time for failovers
- The observe-only mode for fast-start failover enables you to test how fast-start failover will work in your environment. There is no impact on your current configuration or on applications.
- In this mode, no actual changes are made to your Broker configuration. When the conditions for fast-start failover are met, the Broker adds messages to the observer log and broker log indicating that fast-start failover would have been initiated. The logs also contain other details about the actions that will be performed in case of a failover.
Note the following points about the observe-only mode:
- The primary database can enter UNSYNC or LAGGING state without an acknowledgement from the observer or target standby.
- The primary database can be opened even if there is no acknowledgement from the observer or target standby.
Manual failover to the fast-start failover target can be performed without receiving an acknowledgement from the observer.
- Manual failover can be performed even if the pre-condition checks are not met. This includes the following: broker configuration is in UNSYNC or LAGGING state or unobserved state, failover target is invalid, reinstatement is in progress, or a master observer switch is in progress.
- You can switch over or manual failover to a bystander database.
DGMGRL> ENABLE FAST_START FAILOVER OBSERVE ONLY;
Enabled in Observe-Only Mode.
DGMGRL> SHOW CONFIGURATION;
Configuration – hari
Protection Mode: MaxAvailability
delhi – Primary database
chennai – (*) Physical standby database
Fast-Start Failover: Enabled in Observe-Only Mode
SUCCESS (status updated 35 seconds ago)
DGMGRL> disable FAST_START FAILOVER;
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