DBMS high availability by engine: HSR vs Always On vs HADR vs Data Guard
Verdict: Each SAP database engine uses its own native HA technology: HANA uses HANA System Replication, SQL Server uses Always On availability groups, IBM DB2 uses HADR, Oracle uses Data Guard. Do not mix a technology with the wrong engine.
| Criterion | SAP HANA | SQL Server | IBM DB2 | Oracle |
|---|---|---|---|---|
| Native HA technology | HANA System Replication (HSR) | Always On availability groups | High availability disaster recovery (HADR) | Oracle Data Guard |
| Notes | Currently the only supported HANA HA function | Successor to deprecated database mirroring | DB2's own HADR feature | Oracle-specific, not for other engines |
Rules
- For SAP on SQL Server, Always On availability groups are the documented HA/DR approach, analogous to HSR for HANA.
- For SAP on IBM DB2, the recommended DBMS HA is DB2's native High availability disaster recovery (HADR).
- Correct pairings are HANA with HSR and SQL Server with Always On; the other engine pairings are mismatches.
Traps
- Database mirroring is deprecated; Always On availability groups are the SQL Server successor.
- Oracle Data Guard and HSR are engine-specific; neither applies to DB2.