Overview of the high availability solution for SAP

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Read this information to learn about solutions for high availability for SAP systems and SAP system automation.

High availability of an SAP system

As described in Degrees of availability, single points of failure must be eliminated. Db2® data sharing is used to remove the database server as a single point of failure. With SCS, the enqueue server was removed as a single point of failure. The high availability solution for SAP also adds a movable Network File System server (NFS server) and dynamic virtual IP addressing (under z/OS® only) so that application components can be moved. IBM Z System Automation is used to monitor these components and quickly restart them if they fail.

Automating an SAP system

The high availability solution for SAP uses IBM Z System Automation to automate all SAP components.

  • Db2 subsystems
  • Enqueue server
  • Message server
  • Enqueue replication server (if required)
  • TCP/IP
  • NFS server
  • The SAP Java™ gateway server
  • Optionally:
    • The SAP Web Dispatcher
    • The SAP Solution Manager Diagnostics Agent (SMDA)

The optional components, SAP syslog sender, and collector, which existed in earlier SAP NetWeaver releases, are now obsolete. Refer to SAP Note 1041390: SM21: Central system log via HTTP or HTTPS for more details.

By automating all the SAP components, the SAP system can be started, stopped, and monitored as a single resource. This automation provides for the highest level of availability by reducing operator commands, and thus reducing operator errors (see also Operating an SAP system under System Automation control).

The SAP on IBM Z solution is inherently heterogeneous in that it always involves z/OS components and at least one more operating system on which the SAP application servers run.

Benefits of IBM Z System Automation

Because an SAP system has many components that operate in a complex manner, there is a real need to simplify the operation of the SAP system. As more SAP systems are added, this need becomes even greater. Simplifying the operation of the SAP system can help you meet your service level agreements.

IBM Z System Automation (SA) offers system-wide benefits by simplifying the operation of the entire SAP system, which is important when there are multiple SAP systems to manage. It is necessary for the various components of the SAP system to be started and stopped in the correct order. Failure to observe the correct order delays the system's availability.

In IBM Z System Automation, the emphasis is on goal-driven automation. Automation programmers define the default behavior of the systems and application components in terms of dependencies, triggering conditions, and scheduled requests.

The impact of an unplanned incident is further mitigated by the speed of restarting and the degree of automation. The goal-driven design of IBM Z System Automation provides both the speed and a high degree of automation. On the other hand, it avoids the complexity of scripted automation tools, thus reducing automation errors.

The automation manager works to keep systems in line with these goals. It prioritizes operator requests by using its awareness of status, dependencies, and location of all resources to decide what resources need to be made available or unavailable, when, and where. The number of required checks and decisions can be high and a human cannot perform the same tasks as fast and reliably as the automation manager.

Goal-driven automation simplifies operations. Operators request what they want, and automation takes care of any dependencies and resolves affected or conflicting goals. Sysplex-wide automation can also remove the need for specifying extra configurations for backup purposes. Instead, cross-system dependencies and server and system goals can be used to decide which backup system is to be chosen.

Given that the SAP system is generally critical to the operation of the business, and that human errors can occur, the use of an automation tool that responds in a consistent way to a particular event can help deliver on the promise of continuous operation.

You can find more information about IBM Z System Automation on the web: IBM Z System Automation