SAP HANA Replication Modes between Sites

 

Hi all,

We are going to see what are all the Replication Modes between Sites in the SAP HANA Replication setup.

Three Types Of Replication Modes:

• Synchronous (SYNC)
• Asynchronous (ASYNC)
• Synchronous in-memory (SYNCMEM)

Synchronous (SYNC) : The secondary system sends an acknowledgment back to the primary system as soon as the data is received and persisted to the log volumes on disk.

 

When the connection to the secondary system is lost, the primary system continues the transaction processing and writes the changes only to the local disk.

Asynchronous (ASYNC): Asynchronous replication, the primary does not wait until the secondary sends an acknowledgement.

When the connection to the secondary system is lost, the primary system continues the transaction processing and writes the changes only to the local disk. No data loss occurs in this scenario as long as the secondary system is connected. Data loss can occur, when a takeover is executed while the secondary system is disconnected.

Synchronous in-memory (SYNCMEM):The secondary system sends an acknowledgment back to the primary system as soon as the data is received in memory. This option provides better performance because it is not necessary to wait for log I/O on the secondary system. Database consistency across all services on the secondary system is guaranteed. 

Replication Mode have some distance limit to log shipping.

            Replication Mode:                     Distance limit

• SYNC,SYNCMEM                      < 100 KM
• ASYNC                                          > 100 KM

For HANA HA setup – SYNC or SYNCMEM SAP HANA Replication Modes. we can use  between primary and secondary site within the Data-Center

For HANA DR setup–  ASYNC SAP HANA Replication Modes we can use between DC to DR location.