Managing HP Serviceguard Extension for SAP for Linux, December 2013

a synchronous, memory-synchronous, or asynchronous replication relationship. The production
system is the primary system from which replication takes place. Netweaver instances that connect
to the HANA must be disjoined and distinct from one another from the cluster nodes running the
HANA primary and secondary instance.
In an SGeSAP configuration for SAP HANA the following packages are configured:
• A primary package that makes sure that one of the system works as production system.
• A secondary package that makes sure that the other system replicates.
The HANA instances are installed on node-local storage and do not move between cluster nodes
during package failover. Instead of failing over, the mode of secondary is switched to primary
and vice versa. The cluster controls client access capabilities to the production system and
coordinates takeover and role-reversal operations that promote primary instances or demote
secondary instances.
HANA System Replication and Dual-purpose configurations allow the operation of a production
HANA instance together with a non-production HANA instance with certain restrictions. A
non-production HANA instance can be installed on the replication node (node2). However installing
and running additional SAP HANA instances on the primary node (node1) is not supported. Hence,
it is not possible to do a complete role-reversal in which node1 takes over the role of node2 for
both production and non-production instances. In case of a failover of the primary package to
node2 running the secondary instance on a non-production HANA system, SGeSAP ensures the
non-production systems on node2 are halted before it triggers the takeover procedure, that promotes
the secondary HANA instance into the production primary instance.
2.8 Example 6: Scale-out HANA System Replication and Dual-purpose 19