Managing Serviceguard Extension for SAP Version B.05.10, September 2010

1 Designing SGeSAP Cluster Scenarios
This chapter introduces the basic concepts used by the HP Serviceguard Extension for SAP
(SGeSAP) and explains several naming conventions. The following sections provide
recommendations and examples for typical cluster layouts that can be implemented for SAP
environments:
• General Concepts of SGeSAP
• Mutual Failover Scenarios Using the Two Package Concept
• One Package Concept
• Follow-and-Push Clusters with Replicated Enqueue
• Dedicated NFS Packages
• Dialog Instance Clusters as Simple Tool for Adaptive Enterprises
• Handling of Redundant Dialog Instances
• Dedicated Failover Host
General Concepts of SGeSAP
SGeSAP extends HP Serviceguard's failover cluster capabilities to SAP application environments.
SGeSAP continuously monitors the health of each SAP cluster node and automatically responds
to failures or threshold violations. It provides a flexible framework of package templates to easily
define cluster packages that protect various components of a mission-critical SAP infrastructure.
SGeSAP provides a flexible framework of package templates to easily define cluster packages
that protect various components of a mission-critical SAP infrastructure. SGeSAP provides a
single, uniform interface to cluster ABAP-only, JAVA-only, and add-in installations of SAP Web
Application Servers (SAP WAS). Support includes SAP R/3 kernel, mySAP components, SAP
Application Server for ABAP, SAP Application Server for JAVA, and SAP Netweaver based SAP
applications in a range of supported release versions as specified in the separately available
release notes.
The clustered SAP components include SAP ABAP Central Services, SAP JAVA Central Services,
SAP ABAP Application Servers, SAP JAVA Application Servers, SAP Central Instances, SAP
Enqueue Replication Servers, Oracle single-instance databases, MAXDB databases, SAP liveCache
and SAP MDM components. For some platforms, support for liveCache hot standby clusters is
included.
It is possible to combine all clustered components of a single SAP system into one failover package
for simplicity and convenience. There is also full flexibility to split components up into several
packages to avoid unwanted dependencies and to lower potential failover times.
Multiple SAP applications of different type and release version can be consolidated in a single
cluster. SGeSAP enables SAP instance virtualization. It is possible to use SGeSAP to move
redundant SAP ABAP Application Server Instances between hosts to quickly adapt to changing
resource demands or maintenance needs. SGeSAP allows utilizing a combination of HP 9000
and HP Integrity servers in a mixed cluster with heterogeneous failover of SAP packages.
SAP applications can be divided into one or more distinct software components. Most of these
components share a common technology layer, the SAP Application Server (SAPWAS). The SAP
Application Server is the central building block of the SAP Netweaver technology. Each
Application Server implementation comes with a characteristic set of software Single Points of
Failure. These will become installed across the cluster hardware according to several high
availability considerations and off-topic constraints, resulting in an individual configuration
recommendation.
There are various publications available from SAP and third parties that describe the software
components used by SAP applications in more detail. Please refer to these documents to get a
basic familiarity before continuing to read. Also, you can familiarize with Serviceguard clustering
General Concepts of SGeSAP 11