Managing HP Serviceguard Extension for SAP for Linux (May 2013)

Server Instances, SAP Central Instances, SAP Enqueue Replication Server Instances, SAP Gateway
Instances and SAP Webdispatcher Instances.
The module sgesap/mdminstance extends the coverage to the SAP Master Data Management
Instance types. The module to cluster SAP liveCache instances is called sgesap/livecache.
SGeSAP also covers single-instance database instance failover with built-in routines. This ensures
seamless integration and uniform look-and-feel of the solution across different database vendor
technologies. You can use the sgesap/dbinstance module for the SAP Sybase ASE, SAP MaxDB
IBM DB2 or Oracle-based SAP database services.
It is possible to combine all the clustered components of a single SAP software stack into one
failover package for simplicity and convenience. On the other side there is also the full flexibility
to split components up into several packages to avoid unwanted dependencies and to lower
potential failover times. Multiple SAP applications of different types and the release version can
be consolidated in different packages of a single cluster. SGeSAP enables SAP instance
virtualization.
It is possible to use SGeSAP to manually move SAP Application Server Instances between hosts
and quickly adapt to changing resource demands or maintenance needs.
All SGeSAP components support Serviceguard Live Application Detach, Serviceguard Package
Maintenance Mode, and the SAP Online Kernel Switch technologies to minimize planned downtime.
Optional software monitors that check the responsiveness of the major interaction interfaces of the
clustered software components are available.
On top of these four major SGeSAP modules, there are three additional modules that enable easy
clustering of smaller SAP infrastructure software tools (sgesap/sapinfra), allow to manipulate
the behavior of non-clustered SAP instances (sgesap/sapextinstance) and handle SAP
in-memory replication failover policies (sgesap/enqor). The infrastructure tools covered by
sgesap/sapinfra include the SAP sapccmsr, saposcol, rfcadapter, webdispatcher
and saprouter binaries. Depending on the installation type SAP Web Dispatcher can be
configured with either sgesap/sapinstance or sgesap/sapinfra.
The module sgesap/enqor is a special case in that it is a multi-node package (MNP) that must
run on all the nodes of the cluster, if ERS instances are installed. It is particularly useful for clusters
with more than two nodes. It is an optional package that complements the [A]SCS/ERS package
pairs and emulates a Follow-and-Push failover policy between them. Exactly one enqor MNP can
exist per cluster. It automatically covers all [A]SCS/ERS package pairs without further configuration.
The module sgesap/all provides the option to combine all of the above mentioned functionality
into one package with the exception of the enqor MNP. Module sgesap/all is available for
convenience reasons to simplify configuration steps for standard use cases. Only a subset of the
SGeSAP modules can be configured in a package that was created based on sgesap/all.
In many cases, shared access to selected parts of the filesystems is required. This is usually provided
via Network Filesystem Services (NFS). The tkit/nfs/nfs module is separately available and
can be included in any SGeSAP package. It can also run separately as part of a SGeSAP cluster.
SGeSAP provides additional submodules that are transparently included when creating packages
with the above mentioned modules. Explicitly using sub-modules during package creation is not
allowed.
NOTE: HP recommends that any SGeSAP configuration use only modular-based packages.
For more information on modular package creation, see the following sections in chapter
5“Clustering SAP using SGeSAP packages” (page 42):
• Creating SGeSAP package with easy deployment
• Creating SGeSAP package with guided configuration using Serviceguard Manager
8 SAP cluster concepts