High-Availability Data Replication:Table 45 summarizes the various scenarios for restoring data if the secondary database server suffers media failure. The following issues are relevant:
HDR
Server |
Critical Media | Chunks Mirrored | Effect of Failure |
---|---|---|---|
Secondary | Yes | No | Secondary database server fails. Primary database server receives errors. HDR is turned off. Follow the procedure in Restarting After Critical Data Is Damaged. |
Secondary | Yes | Yes | Secondary database server remains online in read-only mode. Follow the procedures in Recovering a Mirror Chunk. |
Secondary | No | No | Secondary database server remains online in read-only mode. Primary database server receives errors. HDR is turned off. Follow the procedure in Restarting After Critical Data Is Damaged. |
Secondary | No | Yes | Secondary database server remains online in read-only mode. Follow the procedures in Recovering a Mirror Chunk. |