SAP High Availability

What Is High Availability?

High availability (HA) is the ability of a system to operate continuously without failing for a designated period of time. HA ensures a system meets an agreed-upon operational performance level. Availability is expressed as a percentage:

• 99% = 87.6 hours of annual downtime
• 9% = 8.76 hours of annual downtime
• 99% = 52 minutes of annual downtime
• 999% = 5 minutes of annual downtime.

High availability usually equals 99.999% or better. HA is achieved by eliminating single points of failure and providing the ability to rapidly resume operations after a system outage with minimal business loss.

What Is SAP High Availability?

SAP has put in place plans and procedures that enable SAP ERP and other critical systems to keep on running. A high-availability solution for SAP needs to achieve four core goals:

• Minimize downtime
• Eliminate data loss
• Maintain data integrity
• Enable flexible configuration.

For example, SAP offers the Standalone Enqueue Server 2 (ENSA2) as a component of Application Server ABAP to provide high availability. It supports two-node and multi-node clusters, which enables switchover to ENSA2 to ensure continued system availability. In addition, SAP High Availability Failover enables SAP Adaptive Server Enterprise (SAP ASE) to work in a cluster of servers in a specific configuration, enabling failover and failback on servers.

Further Resources for SAPinsiders

SAP High Availability Best Practices in AWS. In this webinar, Brett Barwick, Senior Software Engineer of SIOS Technology Corp., and Tamara Astakhov, Senior Partner, Solution Architect for Big Data & Analytics, AWS, discuss best practices for SAP high availability and how to achieve near-zero downtime.

The 15 Most Overlooked Items in Planning for High Availability and Disaster Recovery. In this article, Kurt Bishop, a retired member of SAP America’s Technical Consulting Team, offers advice on how to avoid costly mistakes by sharing the 15 most overlooked items — including the cost of downtime, security issues, loss of personnel and systems, and the importance of testing — and discussing how to incorporate them into recovery planning.

Architecting a High Availability SAP NetWeaver Infrastructure: Strategies for Ensuring a Successful, Cost-Effective Implementation. In this article, Matt Kangas, U.S. Product Manager for SAP NetWeaver Application Server at SAP Labs, provides an overview of HA basics and then discusses the technical details of an HA setup with SAP NetWeaver, including topics such as architectural single points of failure and ways to isolate and protect such failure points.

Vendors that can assist SAP customers with high availability include: AWS, Google Cloud, Microsoft, Managecore, Red Hat, Saberpoint, SIOS, SUSE, Virtustream, and Zebra Technologies.