SQL Server High Availability and Disaster Recovery for SAP Deployment at QR: A Technical Case Study

  • Article

Writer: Danny Tambs

Contributors:  Sanjay Mishra

Technical Reviewers: Prem Mehra, Juergen Thomas, Tim Robinson (QR), Chris Ludbey (QR)

Published: September 2010

 

Queensland Rail (QR) has been running trains in the Australian state of Queensland since the 1860s. Queensland Rail undertook a migration from a z/OS mainframe running DB2 to host SAP. Early versions of SAP for example R/2 only ran on mainframes; however, newer versions of SAP R/3 run on a number of different hardware and software platforms, providing more options for SAP customers. QR engaged Microsoft Services to assist in migrating the database platform underpinning SAP to Microsoft® SQL Server® 2005 by June 2007. This timeframe would enable QR to upgrade SAP to ERP6 running on SQL Server 2005 running in a highly available configuration by 2008. The change of platform to the Windows Server® and SQL Server platforms would provide a much more cost-effective total cost of ownership, as well as the high availability between data centers that was a requirement for QR. Improved performance headroom was also critical, because the load on the system was expected to grow.

QR stressed that achieving maximum availability and near-immediate recovery from a disaster was of highest importance for QR’s operations. QR’s design goals were to eliminate all single points of failure in the architecture, and now, with well thought-out procedures and practices, QR has 99.99x percent uptime, including both planned and unplanned downtime.

This paper is intended for architects and solution integration specialists who want to learn more about SQL Server high availability design patterns that customers use in production to host mission-critical application environments. The focus of this paper is to provide insight into high availability for a SAP implementation project; however, the best practices presented here can be reused to satisfy other database high availability project requirements, not just those that involve SAP.

For more information, please refer to the whitepaper SQL Server High Availability and Disaster Recovery for SAP Deployment at QR: A Technical Case Study.