High availability of SAP HANA with SUSE

SAP HANA and SLES

Improving the performance of CPUs (multi-core architecture), disk access speed and especially the rewriting of certain in-memory application concepts have led to the appearance of SAP HANA, the in-memory database according to SAP.

The SLES HA (High Availability) extension is the Cluster-Linux solution supported by SAP. SLES (SUSE Linux Enterprise Server) for SAP is the first operating system recommended and supported for SAP HANA. Since June 2014, two new HA agents have been developed by SUSE for SAP HANA.

SLES is a flexible, high-availability and high-performance platform for SAP cluster environments. SLES for SAP is automated and standardised. It offers an HA agent for SAP with pacemaker. It also allows installation on HANA in TDI mode. Lifecycles are managed via SUSE Manager.

HA mechanisms with SAP HANA

In general, system redundancy helps to eliminate any SPOF (Single Point of Failure) and ensure business continuity, particularly in the case of failure and recovery. Such redundancy can be set up using mechanisms that are native to SAP HANA.Suse

The cluster configuration on SAP-HANA is multi-nodal.

Replication is included in SAP-HANA from the SPS5 version up. It is implemented either through the online command mode or through the SAP HANA Studio graphic interface.

Suse

There are 4 replication modes, with ascending levels of security and execution speed:

  • Synchronous (mode=fullsync)
  • Synchronous (mode=sync)
  • Synchronous In Memory (mode=syncmem) – mode used for the demonstration below.
  • Asynchronous (mode=async)

The takeover allows recovery on the secondary site of the SAP-HANA instance.

The service IP address and state of replication are not managed automatically during the switch. These operations must be done manually or through a third-party cluster-type product.

Suse

New SUSE Specific Agents for automatic replication

SUSE has developed two new Specific Agents in collaboration with SAP, namely SAPHana Topology and SAPHana contained in a SAPHanaSR Package. These agents are built into the SUSE pacemaker cluster and are used for automatic system-replication management. No extra cost is involved, as the SUSE High Availability suite (aka pacemaker) is already present in the SLES for SAP installed on SAP HANA boxes.

Thanks to these high-availability layers, the service IP address and state of replication can be managed automatically. Fencing therefore needs to be added for the proper functioning of the cluster.

Suse

An automated replication solution is installed in several stages:

  1. Installation of OS - SLES 11 for SAP-SP3
  2. Installation of SAP-HANA SPS9
  3. Setting up replication
  4. Backup and manual takeover tests
  5. Installation of SUSE cluster: not necessary
  6. Installation of SAPHanaSR package
  7. Configuration of SUSE cluster
  8. Automatic switch tests (loss of primary site / loss of secondary site / loss of primary node network / loss of private "split-brain" network) 

An on-screen demonstration of failure and recovery scenarios was done to show that the tests were conclusive.

The SLES HA solution is a true high-availability solution on SAP-HANA.

To find out more about SAP-HANA replication with the SUSE cluster, watch the oXya video: https://www.youtube.com/watch?v=yXH7ZkWN-qM

oXya, expertise in SUSE Manager and SLES HA for SAP HANA

oXya has been developing a strategic technological partnership with SUSE over the past 5 years. With teams that receive regular training in the latest innovations developed at SUSE, oXya has specialised expertise in SLES operating systems for SAP. By setting up automatic installations based on SAPNotes for numerous customers, oXya is able to deploy complex architectures like clusters or SAP-HANA in TDI (Tailored Datacenter Integration) mode.

This expertise also enables us to set up high-availability mechanisms from SUSE with a single SAP-HANA instance.

Top