If the SRL overflows and log overflow protection is set to autodcm or dcm, the Secondary can be incrementally synchronized using the Replay DCM task. After the Primary and all the Secondaries reconnect, the DCM resynchronization process must be started to transfer data from the Primary to the Secondary. The Replay DCM task enables you to replay an active DCM and incrementally resynchronize the Secondary after SRL overflow.
During DCM resynchronization, VVR does not maintain the order of updates to the Secondary. As a result, the Secondary remains inconsistent until the resynchronization operation is complete. Note that if the Primary becomes unavailable during resynchronization, the applications cannot be restarted on the Secondary.
If the Secondary volumes are mirrored, you can break off mirrors to retain consistent (though out-of-date) copies of data until the resynchronization is complete. Use the snapshot feature to do this if snapshots exist.
To incrementally resynchronize the Secondary after SRL overflow
- Data is transmitted to the Secondaries only after all the Secondaries are connected to the Primary.
- All the Secondaries taking part in the resynchronization must remain connected for the resynchronization to continue. The resynchronization pauses if any of the Secondaries disconnects or is manually paused.
- While resynchronization is in progress, the RDS View displays the value DCM in the Logging To column.
For details about each method, refer to Transferring the Primary role.