SAP HANA Recovery Kit Overview

The SAP HANA Recovery Kit is compatible with SAP HANA Platform 2 (SP04 or later).

SAP HANA provides three different mechanisms to increase availability.

• Host Auto-Failover – At least one standby node added to a SAP HANA system. These nodes are configured to work in standby mode. If the required processes or databases are not active, LifeKeeper will attempt to restart them. In case of an unsuccessful restart of the processes on the primary node, LifeKeeper will attempt to bring the database in-service on the backup node, register that node as primary master in SAP HANA System Replication, and register the previous primary node as the secondary replication site. If the previous primary node cannot be configured as the secondary SAP HANA System Replication site, the resource will be marked as Failed (OSF) on that node until the problem is corrected and it can be successfully registered. Once the previous primary node has been successfully registered as a secondary replication site, LifeKeeper will update the state of the SAP HANA resource on the node to Standby (OSU).

• Storage Replication – The storage used on the primary SAP HANA node replicates all data to another SAP HANA node. This replication works without a control process from the SAP HANA system. The storage replication is provided by hardware partners.

• System Replication – SAP HANA replicates all data from the primary SAP HANA node to a backup node by use of SAP’s own built-in replication framework. Data is constantly pre-loaded on the secondary SAP HANA node.

With the SAP HANA Recovery Kit, SAP HANA systems, utilizing System Replication, can be protected and administered through SIOS LifeKeeper.

The Recovery Kit is able to start the SAP HANA system on all nodes and perform the takeover and replication site registration processes of SAP HANA System Replication. To ensure the functionality of the SAP HANA system, the following processes and states are continuously monitored:

• SAP Host Agent on all nodes
• SAP Start Service (sapstartsrv) of HDB instance on all nodes
• State of SAP HANA database on all nodes
• State of SAP HANA System Replication mode (primary on active node, sync|syncmem|async on secondary node)

If the required processes or databases are not active, LifeKeeper will attempt to restart them. In case of an unsuccessful restart of the processes on the primary node, LifeKeeper will attempt to bring the database in-service on the backup node, register that node as primary master in SAP HANA System Replication, and register the previous primary node as the secondary replication site. If the previous primary node cannot be configured as the secondary SAP HANA System Replication site, the resource will be marked as Failed (OSF) on that node until the problem is corrected and it can be successfully registered. Once the previous primary node has been successfully registered as a secondary replication site, LifeKeeper will update the state of the SAP HANA resource on the node to Standby (OSU).

In case of an invalid state of the SAP HANA System Replication, the SAP HANA resource is also placed in the state “Out of Service – Faulty” (OSF). It has to be decided with the help of a database administrator whether a takeover is to be performed or how the SAP HANA System Replication mode should be corrected.

When carrying out the “Out of Service” action for an SAP HANA resource in LifeKeeper, only the database on the primary node is stopped by default. The database on the secondary node remains active and retains its SAP HANA System Replication mode.