Ensuring Continuity: High Availability and Disaster Recovery Solutions by SAP HANA
SAP HANA, a leading in-memory database, is designed not only for high performance in data analysis and real-time transactions but also for robust data integrity and rapid recovery in the event of failures. Ensuring continuous operation with minimal data loss is of utmost importance, and SAP HANA is equipped with a comprehensive set of mechanisms to achieve this.
We would be happy to support you in the following topics:
Disaster recovery
| Backups | Regularly scheduled backups are crucial for any enterprise data management strategy. SAP HANA allows databases to be periodically copied and stored in secure locations, ensuring data can be restored following disruptive incidents. More details can be found in the SAP HANA Administration Guide, specifically under Database Backup and Recovery. |
| Storage Replication | This involves the continuous mirroring of data from primary storage to backup storage across a network, ensuring that a real-time copy of the database is always available at a secondary location. For in-depth information, refer to the Storage Replication section in the SAP HANA Administration Guide, particularly in the context of Availability and Scalability, and SAP Note 1755396 – Released DT solutions for SAP HANA with disk replication. |
| System Replication | SAP HANA updates a secondary system continuously from the primary system, including loading in-memory tables. This ensures that in the event of a primary system failure, the secondary system can take over with up-to-date data. Detailed guidance is provided in the System Replication section of the SAP HANA Administration Guide. |
Fault Recovery
| Service Auto-Restart | Automatically restarts stopped services on the host, enhancing system resilience by reducing downtime. Detailed procedures and settings are described in the Service Auto-Restart section of the SAP HANA Administration Guide. |
| Host Auto-Failover | In the event of a host crash, SAP HANA automatically fails over to a standby host within the same system, ensuring continuous operation. This is covered extensively in the Host Auto-Failover section of the SAP HANA Administration Guide. |
Additional Measures for Data Integrity and System Availability
| Disaster Tolerance Solutions | Based on hard disk I/O subsystem replication, SAP HANA’s disaster tolerance capabilities are designed to handle complete data center decommissions. During a takeover, systems at a secondary location (cold standby) are activated, and the replication between the locations is interrupted to switch operations to the secondary servers. |
| Asynchronous and Synchronous Replication | While synchronous replication is preferred for shorter distances due to its real-time nature, asynchronous replication can be suitable for longer distances where latency may impact performance. The choice between these depends on specific business needs and network configurations. |
| Certification and Compliance | Solutions must be certified by SAP and by SAP HANA appliance hardware partners, ensuring that they meet rigorous standards required for efficient and secure operations. |
| Active/Active Read | Active/Active (read access enabled) enables read access to the secondary system during SAP HANA system replication. This feature is built into the system replication solution and is enabled with the logreplay_readaccess operating mode. To set up Active/Active (read access enabled) system replication, follow the procedure described for setting up system replication in SAP HANA with hdbnsutil and select the logreplay_readaccess operating mode. For more information about this operating mode, see the SAP HANA system replication operating modes section. |
High Availability
| Redundancy | Multiple layers of redundancy across hardware, software, and network components help safeguard against failures. This includes everything from redundant power supplies to advanced networking setups that ensure data is continuously accessible even if parts of the system fail. |
| Persistence | Transaction logs, savepoints, and snapshots are continually persisted, which supports system restarts and rapid recovery from host failures with minimal delay and no data loss. |
| Standby and Failover | Dedicated standby hosts are ready to take over immediately if the primary hosts fail, significantly reducing recovery time. |
