Easily leverage Hana HA cluster functionality
Without a solid grounding in IT infrastructure or operations issues, Hana projects stand on feet of clay.
Companies must ensure that business-critical SAP applications such as S/4 or BW/4 Hana can be used at virtually any time. After all, business continuity must neither falter for a long time nor lie completely idle.
On the IT infrastructure/Hana agenda, the topic complex of High Availability (HA) is still at the top and, incidentally, is discussed in one way or another at practically every Suse SAP workshop, for example.
As in previous versions, the current version 12 of Suse Linux Enterprise (SLES) for SAP Applications provides SAP Suse customers with the High Availability Extension (HAE) including disaster recovery (DR) functionality from the outset. Usable for both Any DB and Hana DB deployment.
Important here:
The High Availability Extension in SLES for SAP Applications is a complete HA open source solution package available to SAP Suse customers for use free of charge.
This eliminates the need to spend additional money on an additional cluster resource management solution for Hana deployments.
Incidentally, Suse HAE for SAP Applications is based on the open source solution Pacemaker.
Of course, the Suse HA solution is integrated into the SAP system management (Solution Manager) just like the operating system platform Suse Linux Enterprise Server for SAP Applications.
At the heart of SAP's Hana HA concept is Hana System Replication (SR). However, the handling/usage is usually done manually.
Of course, there are advantages to SR automation, which can result in an increase in SLAs.
A Hana system replication runs via a memory preload in a cluster (in minimum 2-node cluster). In the event of a failure, automatic switchover takes place using Suse HAE for SAP Applications.
Disaster Recovery
In case of a necessary disaster recovery scenario, it is possible that a Hana System Replication is performed by an additional asynchronous replication to another site (e.g. another Data Center) to achieve DR coverage.
There is also a "cost-optimized approach". Here, a memory preload (on a system constantly running in parallel) is dispensed with. A second node is also used here.
However, it acts mainly as a test and development system, and Hana System Replication is run or used on the second node exclusively in the HA case.
Compared to a high-availability environment with synchronous memory preload, Hana recovery naturally takes longer here.
Nevertheless, this approach means a beneficial minimization of investment/operating costs. In a possible DR scenario, replication to the secondary site is also asynchronous again.
Based on Hana Resource Agents (RA) from Suse, Hana database instances and replications can be administered and managed.
These resource agents also enable intelligent and at the same time simplified use of cluster configurations. And much easier than was the case in the past.
Conclusion
In summary, the Suse High Availability Extension (HAE) provided with SLES for SAP Applications has been a proven and leading high availability solution for improving business continuity/high availability including disaster recovery functionality for SAP solutions for years now.
Together with SAP, it was optimized for Hana use through additional developments.
It increases the SLAs for Hana operation, simplifies the handling of cluster configurations and can be used for both scale-up and scale-out system environments. Whereby there is a "controlled Availability" (cA) for the scale-out deployment.
