Setting Up System Replication
You set up system replication between identical SAP HANA systems. Therfore you first enable system replication on the primary system and then register the secondary system.
Prerequisites
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You comply all prerequisites for SAP HANA system replication.
For more information, see: . -
You have the authorizations required.
For more information, see Standard Permissions.
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You have assigned the roles and groups required.
For more information, see Standard Roles and Groups.
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You have installed and configured two identical, independently-operational SAP HANA systems – a primary system and a secondary system.
For more information, see Configuring Instances.
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The secondary system must meet the following criteria with respect to the primary system:
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It must have a different host name, or host names in the case of a distributed system. System replication between two systems on the same host is not supported.
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It must have the same number of nodes and worker hosts. This implies that if there is a standby host on the primary system it need not be available on the secondary system.
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It must have the same software version or higher. You need at least SAP HANA1.0 Revision 81 or higher.
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It must have the same SAP system ID (SID) and instance number.
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The primary replicates all relevant license information to the secondary. An additional license is not required.
For more information, see SAP Note 2211663
.
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It must have the same system configuration in the system properties files (*.ini files). Any changes made manually or by SQL on one system must be manually duplicated on the other system.
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You have installed SAP Adaptive Extensions.
For more information, see https://help.sap.com/viewer/p/SAP_ADAPTIVE_EXTENSIONS.
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SAP Host Agent must be able to write to the operations.d subfolder. If this is not possible, because it is a mounted NFS share, extract the latest SAP Adaptive Extensions into this share.
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To detect, manage, and monitor SAP HANA as a database, ensure the following:
- You have installed the hdbclient on each SAP HANA host.
- You have specified a database user either in the SAP Landscape Management
instance configuration or on the SAP HANA
system in the <HANA-SID> SAPDBCTRL hdbuserstore key for
the <hana-sid>adm user. For more information, see SAP
Note 2050537
.
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To allow uninterrupted client communication with the SAP HANA system, your high-availability solution has to support client connection recovery. You can use SAP Landscape Management for connection recovery after disaster recovery with network-based IP redirection.
For more information, see Assigning Virtual Host Names to Networks.
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The required ports must be available. The same instance number is used for primary and secondary systems. The instance number+1 must be free on both systems, because this port range is used for system replication communications.
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You have verified that the log_mode parameter in the persistence section of the global.ini file is set to normal for both systems. Log mode normal means that log segments are backed up. Log mode overwrite means log segments are freed by the savepoint (therefore only useful for test installations without backup and recovery).
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You have performed a data backup or storage snapshot on the primary system. In multiple-container systems, the system database and all tenant databases must be backed up. This is necessary to start creating log backups. Activated log backup is a prerequisite to get a common sync point for log shipping between the primary and secondary system.
For more information, see SAP HANA Database Backup and Recovery.
Procedure
Next Steps
Perform SAP HANA operations or SAP HANA processes as required.
