Managing Serviceguard Extension for SAP Version B.05.10, December 2012

2 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
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 single, uniform interface to cluster ABAP-only, JAVA-only, double-stack and
split-stack installations of SAP Netweaver based SAP applications. These are supported in a range
of versions as specified in the separately available release notes.
The clustered software instances include SAP ABAP Central Services, SAP JAVA Central Services,
SAP ABAP Application Servers, SAP JAVA Application Servers, SAP Central Instances, SAP Enqueue
Replication Servers, SAP Web Dispatcher, SAP Gateway, IBM DB2 databases, Oracle
single-instance databases, SAP MaxDB and Sybase ASE databases, SAP liveCache and SAP MDM
components. For some platforms, support for liveCache hot standby clusters is included.
Software monitors that can check the responsiveness of the major interaction interfaces of the
clustered software components are included. SAP Netweaver stack and SAP Livecache monitors
allow planned software shutdowns when the cluster is up and running.
For simplicity and convenience, all clustered components of a single SAP system can be combined
into one failover package. Also, components can be split up into several packages to avoid
unwanted dependencies and to lower potential failover times.
Multiple SAP applications of different types and release version can be consolidated in a single
cluster. SGeSAP enables SAP instance virtualization. SGeSAP can be used 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
and virtualization by reading the Serviceguard product manual, Managing Serviceguard, at
www.hp.com/go/hpux-serviceguard-docs —> HP Serviceguard —> User guide.
Serviceguard packages can be distinguished into legacy packages and module-based packages.
SGeSAP provides solutions for both approaches. SGeSAP consists of several SAP-related modules,
legacy script templates, SAP software service monitors, as well as specialized additional features
to integrate hot standby liveCache scenarios, HP Workload Management scenarios, and HP Event
Monitors.
There are three major Serviceguard modules delivered with SGeSAP. The standard SAP Netweaver
web application server stack includes a Serviceguard module called sgesap/sapinstance.
This module can be used to easily add a set of SAP instances that belong to the same
Netweaver-based system to a module-based Serviceguard package. The package can encapsulate
8 Designing SGeSAP Cluster Scenarios