Managing Serviceguard Extension for SAP on Linux (IA64 Integrity and x86_64), February 2008

Understanding Serviceguard Extension for SAP on Linux
Designing Serviceguard Extension for SAP on Linux Cluster Scenarios
Chapter 116
Some Web Application Server installations automatically install more
than one Central Instance at a time. E.g. a SAP Exchange Infrastructure
3.0 installation creates a DVEBMGS instance as well as a System Central
Service SCS instance using different Instance Numbers.
This SCS instance is technically identical with an ASCS instance, but it
delivers its services to the J2EE Engines instead of the ABAP Engines of
the Web Application Server.
NOTE SCS Instances are clustered with the package type (jci). The naming
reflects that the SCS Instance delivers the critical Central Instance
Services for the JAVA portion of the Web Application Server.
A one-package installation for the SAP Exchange Infrastructure would
need to include three mission-critical components: the database, the
Central Instance for ABAP and the SCS Instance for JAVA. The package
would now be called (dbcijciSID).
It is allowed to create (cijciSID) packages that just fail over SAP
software excluding the database which might be secured with different
means.
It is also possible to split a DVEBMGS instance into an ASCS and a Dialog
Instance. This process is described later in this document. As a result, a
single SAP System may have a SCS and an ASCS Instance at the same
time. SAP Web Application Server 7.0 provides installation options that
provide this combination of SCS and ASCS out of the box.