HANA System Replication takeover decision guideline
In past few months we SAP IT BSS Database team are working with P&I HANA Dev team on overall improvement for HANA System Replication (HSR) feature and usage in operations. In our big 5 HANA production databases (ICP, ISP, BWP, BCP, BCS) we are using HSR feature to ensure high availability to ensure business continuity.
HSR solutions not only help in critical infrastructure outage scenario but can help in bring system back online early during planned downtime and any emergency software crashes. Based on our past experience and by keeping requirement of minimizing downtime we worked with HANA development team to come up with procedure which will help in 3 main aspects:
- Configuration of HSR parameters: We identify set of parameters depending on nature of system like OLTP (CRM or ERP) or OLAP(BW) which help in bringing secondary site online quickly
- Quick and correct decision about HSR takeover: HSR can help fast system recovery in more than one scenarios but there are certain scenario where HSR takeover to secondary site may not beneficial
- Check data consistency at a time during situation: While making HSR takeover decision it is extremely important to check data consistency between primary and secondary and there are multiple ways to ensure data consistency between two sites. This depends also on the way how HSR is implemented.
Guidelines cover above aspects in detail and explain all the possible scenarios and solutions and documented at OSS note 2063657 as a general guidelines for external customer and at WIKI link specific to SAP internal production systems.
These artifacts are great examples of co-innovation between various teams and constant efforts towards stabilization of product and helping our customer by delivering predictable and reliable solutions. By this all SAP customers get benefit from procedures we develop with internal system operations and being Early Adopter.
Devang on behalf of SAP IT BSS Database Team