Which modes of SAP HANA system replication are available?
The following SAP HANA system replication modes exist:
| Mode | Details | Behaviour when secondary system is not available |
| Synchronous | Primary system waits until secondary system has received data and persisted it to disk. | Primary system waits until global.ini -> [system_replication] -> logshipping_timeout is exceeded (default: 30 s) and then proceeds without replicating data. |
| Synchronous in-memory | Primary system waits until secondary system has received data. | Primary system waits until global.ini -> [system_replication] -> logshipping_timeout is exceeded (default: 30 s) and then proceeds without replicating data. |
| Synchronous full sync (SPS 08 and higher) | Primary system waits until secondary system has received data and persisted it to disk. | Primary system is blocked until secondary system becomes available. |
| Asynchronous | Primary system doesn't have to wait for secondary system. | Primary system proceeds without replicating data. |