SAP SAP HANA

Ensuring high availability in SAP HANA

Publish Date: February 11, 2021

Any SAP application of an enterprise tends to carry its value across many critical touchpoints, be it planning your resources, business processes, or improving workforce satisfaction, customer service. SAP has become the lifeline of businesses that depend on running operations seamlessly in the digital-first world. Consequently, businesses also need continuity that ensures all critical systems and applications are available at all times, even in the face of disruptions or uncertainties.

In this regard, SAP’s HANA comes with various kinds of high availability mechanisms, supporting a broad range of recovery scenarios from different issues. In this blog, we will be diving briefly into two such mechanisms – Automated SAP HANA System Replication in scale-up using pacemaker cluster of SUSE Linux, and HANA high availability in a scale-out scenario using Host Auto-Failover.

SAP HANA System Replication on SUSE Pacemaker cluster (Scale-up scenario)

SUSE offers a scale-up resource agent package called the ‘SAPHanaSR’. This kind of system replication helps replicate enterprise database data from one computer to the other so that you can compensate for database failures. The resource agent of RA performs the check of the SAP HANA database scenarios after being configured as the master/slave resource. In the scale-up scenario, the master takes up the responsibility of SAP HANA databases running on primary mode. In contrast, the slave takes up instances that operate with synchronous or secondary status.

One significant benefit of such a performance-optimized scenario is allowing read access on the secondary database site. This also has the advantage of enabling enterprises to use their SAP systems and SAP HANA databases without interruptions or high budgets.

SAP HANA high availability using Host Auto-Failover (scale-out scenario)

Host auto-failover is a well-known local fault recovery solution that can be leveraged as an alternative way to replicate the system. In this, one or more standby hosts can be added to the SAP HANA system and then configured further to work in standby mode. It is important to note that the database on the standby hosts neither contain any data, nor do they accept any requests or queries in standby mode.

However, when an active worker host fails, the standby host immediately and automatically takes its place. This is typically achieved using a shared network storage server, a distributed file system, or even with vendor-specific solutions that can dynamically mount networked storage as and when failover happens.

Eliminating redundancies and chances of failure

The key to accomplishing high availability is the elimination of all the points of failure with proactiveness. Be it redundancies in hardware networks or data centers, SAP has been designed to support a wide range of high availability options. It ensures that data reliability in the event of failures is well maintained while the operations resume back at the earliest with data being loaded at a faster pace.