Managing Serviceguard Extension for SAP, December 2007

SGeSAP Cluster Administration
Mixed Clusters
Chapter 6 307
Mixed Clusters
Platform changes from HP 9000 hardware to Integrity systems are
complex and require a significant investment. Changing the hardware
for a multi-node cluster at once is an expensive undertaking. It is
possible to perform this change step by step, replacing only one server at
once with SGeSAP. During this transition phase, the cluster will
technically have a mixed layout. However, from SAPs perspective it’s still
a homogeneous HP-UX system.
Most of SAPs business transactions are still written in ABAP, SAPs own
programming language. All programs are stored as source code in the
database and translated at the first time of execution if not already
delivered in a translated form. At this first time of execution, the
translated code is also stored in the database for next time use. This
table is usually sized to hold the code for one platform. If you deploy
application servers of different platforms within a single SAP system,
this table needs to be sized appropriately to avoid unnecessary
translations.
A mixed cluster containing both HP 9000 and Integrity HP-UX nodes
must fulfill the following prerequisites:
• The system needs to be based on single-instance ORACLE database
technology.
• All cluster nodes are installed with HP-UX 11i v2 (ud2) or higher.
• Serviceguard 11.16 or Serviceguard 11.17 is required
• The bundles of the HP Serviceguard Storage Management Suite are
not allowed in SAP mixed clusters
• The cluster setup must follow the storage layout option 1 of chapter 2
(NFS-based)
• SGeSAP packages that do not contain database components can be
configured to run on any node in the cluster. This includes ci, jci,
[a]rep and d package types.
• SGeSAP database instance packages must be configured to run only
on either Integrity or HP 9000 nodes. This includes db, jdb and lc
package types and all package types composed of these.