Managing Serviceguard Extension for SAP on Linux (IA64 Integrity and x86_64), April 2009

1 Understanding Serviceguard Extension for SAP on Linux
HP Serviceguard Extension for SAP on Linux (IA64 Integrity and x86_64) hereafter documented as HP
Serviceguard Extension for SAP on Linux or SGeSAP/LX, extends HP Serviceguard's failover cluster capabilities
to SAP application environments. Serviceguard Extension for SAP on Linux 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.
Serviceguard Extension for SAP on Linux provides a single, uniform interface to cluster SAP R/3, mySAP,
SAP Web Application Server (SAPWAS), SAP Netweaver and SAP standalone J2EE based SAP applications
in a vast range of supported release versions. The Serviceguard Extension for SAP also clusters underlying
databases, and SAP liveCache.
It is possible to combine all clustered components of a single SAP system into one failover package for
simplicity and convenience. On the other side there is also the full flexibility to separate SAP components
up into several packages. In the case of a failure of one of these SAP components only the failed component
has to be failed over instead of the complete instance thereby lowering overall failover times.
Multiple SAP applications of different type and release version can be consolidated in a single cluster.
Serviceguard Extension for SAP on Linux can quickly adapt to changing load demands or maintenance
needs by moving SAP Application Sever instances between hosts.
This chapter introduces the basic concepts used by Serviceguard Extension for SAP on Linux and explains
several naming conventions. The topics include:
• Designing Serviceguard Extension for SAP on Linux Cluster Scenarios
Failover Scenarios Using One and Two Package Concepts•
• Robust Failover Using the One Package Concept
• About SAP Client/Server Architecture
About Two-Tier Client/Server Architecture•
• About Three-Tier Client/Server Architecture
• About SAP Three-Tier Dual-Stack Configuration
Designing Serviceguard Extension for SAP on Linux Cluster Scenarios
SAP applications can be divided into one or more distinct software components. Most of these components
share a common technology layer, the SAP Web Application Server (SAPWAS). The SAP Web Application
Server is the central building block of the SAP Netweaver technology. Each Web 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. It is recommended to refer to these documents to get a basic
familiarity. It is also recommended to familiarize with Serviceguard clustering by reading the Serviceguard
product manual Managing Serviceguard , eleventh edition or higher. The latest version can always be found
at docs.hp.com/en/ha.html#Serviceguard%20for%20Linux.
Each software Single Point of Failure (SPOF) defines a Serviceguard Extension for SAP on Linux package
type. Serviceguard Extension for SAP on Linux follows a consistent naming convention for these package
types. The naming conventions were created to be independent of SAP software release versions. This allows
using a similar approach for each SPOF, regardless of whether it appears in the latest SAP Netweaver stack
or a SAP software that was released before the first design of SAP Web Application Server. Older SAP
components sometimes only support a subset of the available clustering options.
The following sections introduce different Serviceguard Extension for SAP on Linux package types and provide
recommendations and examples for the cluster layouts. Each SAP uses a <SID> which is an acronym for
System IDentification for defining which components belong to the same SAP installation. For the following
Designing Serviceguard Extension for SAP on Linux Cluster Scenarios 13