SAP HANA Dynamic Tiering: Tips and Tricks for Point-in-Time Backup and Recovery

Here are two issues you might encounter while performing point-in-time recoveries.

When a Point-in-Time Recovery Can’t Find a Log Backup on the Latest Timeline

Issue: If you see the following error message, it means your point-in-time recovery of SAP HANA with dynamic tiering didn’t succeed:

[18847]{-1}[-1/-1] 2015-05-25 23:44:04.143136 i FedTrace
FederationContext.cpp(00634) : FederationException created 0x00007feee3f6bd10:
Exception 10000: (__esstore$) [SAP][ODBC Driver]RESTORE unable to find a log backup
on the latest timeline

This behavior occurs if the timestamp provided is very close to that of the data backup, and there are no transactions that need replaying from the log backups.

Solution: When you see this error, perform a data-only recovery instead of a point-in-time recovery.

When a Point-in-Time Recovery Leaves Dynamic Tiering Service in Utility Mode

Issue: In SAP HANA dynamic tiering version SP 12 and earlier, you might unintentionally switch the dynamic tiering service to utility mode if you perform the following scenario, of a point-in-time recovery from a backup where dynamic tiering was not installed:

1. Install an SAP HANA system and set up a database.
2. Perform a full database backup.
3. Add the dynamic tiering service, and provision the dymamic tiering service to a database.
4. Recover the database from an earlier full backup without using the delta backup option.

In this scenario, you may find the dynamic tiering service running in utility mode when the recovery completes.

Solution: To avoid this issue altogether, perform a full database backup after adding the dynamic tiering service to the SAP HANA system. This allows the recovery of the database to work properly (Create Extended Storage in the SAP HANA Dynamic Tiering: Administration Guide advises a full backup immediately after you create extended storage).

If the dynamic tiering service is running in utility mode (because you haven’t performed a full database backup after adding the dynamic tiering service to the HANA system), re-provision the dynamic tiering service to the database to resolve this issue.

See the SAP HANA Dynamic Tiering: Administration Guide for more information on SAP HANA dynamic tiering troubleshooting (in Troubleshooting), as well as performing point-in-time recoveries (in Recovering SAP HANA Databases with Dynamic Tiering).