Managing HP Serviceguard Extension for SAP for Linux, December 2013

Figure 1 One-package failover cluster concept
DBCI package moved and
required resources freed
up in the event of a failure
SGeSAP Cluster
One-Package Concept
Node 1 Node 2
Application Servers
dbciC11
QAS Systems
Dialog
Instances
Shared Disks
LAN
To maintain an expensive idle standby is not required as SGeSAP allows utilizing the secondary
node(s) with different instances during normal operation. A common setup installs one or more
non-mission critical SAP Systems on the failover nodes, typically a SAP Consolidation, Quality
Assurance, or Development Systems. They can gracefully be shutdown by SGeSAP during failover
to free up the computing resources for the critical production system. For modular packages, the
sgesap/sapextinstance module can be added to the package to allow specifying this kind
of behavior.
Development environments tend to be less stable than production systems. This must be taken into
consideration before mixing these use-cases in a single cluster. A feasible alternative would be to
install Dialog Instances of the production system on the failover node.
12 SAP cluster concepts