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Oracle and SAP have conducted
many certification tests on selected platforms. Tests have shown a
viable combination of RAC with the SAP system. One such test was
done using the SAP R/3 4.6D and Oracle 9i RAC on a HP Tru64 UNIX
Cluster. Many customers have implemented SAP with an Oracle RAC
database. Readers are urged to check with the SAP vendor for the
Also see the website for
mySAP architecture requires more
and more databases for the different modules. At the same time, the
SAP modules in a mySAP.com environment are not independent, e.g. SAP
SD, SAP CRM, and BW interact and share data. To guarantee the
required consistency within all these databases, SAP has developed a
new method or strategy of Multiple Components in One Database (MCOD).
MCOD is a new feature in the installation process for mySAP.com
components. It provides the capability of installing several
components independently into one single database.
As shown in Figure 11.2, the
data needs are consolidated into one large database system, aided by
the RAC system.
Figure 11.2: mySAP , MCOD and
Oracle RAC Database
With Oracle 10g RAC, nodes can
be optimally customized for dedicated workloads such as CRM, HR, SD,
and retail. By utilizing different database instances for these
functional modules and batch-centric modules, they can be fine tuned
without affecting each other.
By having a single database,
administrative flexibility and cost savings are achievable. Running
all the related SAP modules in only one database guarantees the
consistency and availability of current data. However, as all the
eggs are kept in one basket, it becomes much more important to
protect the MCOD database for high availability and also to provide
acceptable levels of performance. The Oracle RAC database system
meets these challenges very well.
Some database systems require
different parameterization, depending on the transactional behavior
of the application. For these database systems, a separate
installation of OLTP and OLAP systems is necessary. With the
implementation of RAC-based multiple instances, a specific instance
can be assigned to a specific SAP module, and it can have its own
set of parameters or customization.
Siebel and RAC
The Siebel eBusiness application
suite is another important packaged application supporting business
operations. Siebel eBusiness application suite provides an
integrated set of solutions for sales, marketing, customer service,
and partner organization.
Siebel suite is developed on
multi-tier models with application clients, application servers, and
backend database layers. As shown in Figure 11.3, the client
interacts with the middle tier and the middle tier accesses the
database. The business logic is in the middle tier, also known as
the Siebel application server. The business logic is encapsulated in
one or more server components. These server components provide
services to both the interactive and the batch operations.
Typically, the following components make up the middle tier: the
object manager, assignment manager, enterprise integration manager (EIM),
and WorkFlow, etc.
Figure 11.3: Siebel Architecture
The Oracle database has been an
important backend database choice for many Siebel customers. With a
heavy reliance on the database system by Siebel servers, any
malfunction in the database layer cripples the entire application
framework. Any database component can become a single point failure
for the whole Siebel suite. Therefore, a clustered database such as
a RAC database, provides true high availability and scalability.
When one of the nodes fails along with the database instance, the
other surviving instances can still provide the database resources.
Siebel can also leverage the RAC
database’s ability to provide scalability. As the number of users
increases, Siebel Servers can be added to support and maintain
performance levels. At the same time, database access increases. The
Oracle database server can provide the same type of growth. As the
need arises, additional nodes can be added to support the extra
Another important feature of RAC
is the ability to use a selective database instance for a specific
group of application servers. This allows the more critical
application needs to be prioritized and a specific database instance
to be assigned to avoid conflicts and contention.
At the time of writing, tests
are being conducted to certify the Siebel backend database with the
Oracle RAC system. The reader is urged to consult with Siebel to
enquire about the certification status.