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Oracle Grid & Real Application Clusters. To get immediate
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The Oracle eBusiness suite,
formerly known as Oracle Applications, is a collection of integrated
software applications that provide a complete business solution. It
consists of many products or modules, supporting a variety of
business functions. Some of these product families are: financials,
supply chain, human resource management (HRMS), manufacturing,
projects, and public sector and customer relationship management
Oracle eBusiness suite is
implemented in three-tier architecture. These tiers are:
* Desktop tier or Presentation
layer: Comprised of a Web browser and Oracle initiator.
* Application tier: The middle
tier consists of a Web server, forms server, concurrent processing
server, report server, administration server, and optionally, the
* Backend database tier: The
Oracle database server, a single stand-alone or a clustered Oracle
As shown in Figure 11.4, the
database layer in the Release 11i technology stack occupies a
pivotal role in providing transactional and control data for the
entire suite of applications.
The database provides key
functionality by storing data, and is heavily used by all the
modules. It is common for all necessary functional data storage to
take place there.
Figure 11.4: Oracle Applications
Architecture and Technology stack
The critical demands placed on
the application suite for running the business operations, handling
increased workloads, and maintaining adequate performance levels
have become a real challenge. Keeping the eBusiness suite database
online 24/7 is mandatory in order to maintain the enterprise
operation. To improve overall performance, the time taken for batch
jobs and provide fast online response times, the middle tier is
usually expanded with additional application servers. This approach
generally causes another bottleneck in the database layer.
The Oracle Database 10g RAC
database is a good solution to meet these challenges. With the
availability of multiple database instances, it becomes possible to
service a specific group of application servers with a specific
database instance, and so on. This is done while still maintaining a
single database. Database resource consumption by different
functional units is effectively separated.
The architecture of multiple
application servers in the technology stack can take advantage of
multiple Oracle database instances to work in different computing
environments. By grouping the application servers for database
access, scalability and high availability is achieved. The recent
release of the Oracle eBusiness 11i suite (11.5.x) is certified with
the Oracle RAC database system.
An example will help to explain
a typical Oracle eBusiness suite. As shown in Figure 11.5, the
middle tier is deployed with many application servers. They are
grouped into the form server, HRMS server, portal, iExpense, and
concurrent manager server. All the middle tier servers exhibit a
particular personality in terms of their functionality. By providing
the RAC database system as a backend, application servers get many
choices. Based on functionality, the application servers can be
configured to access and update a particular database instance.
Figure 11.5: Oracle eBusiness
suite using Oracle RAC database
For instance, form servers can
connect to instance-1. HRMS and the portal connect to instance-2,
and iExpense and concurrent managers connect to instance-3. This
method uses all the instances in a partitioned way. This utilizes
the instances uniformly and avoids hot spots. At the same time, with
the help of the TAF configuration, high availability of the database
server is achieved.
As the business grows and
concurrent users increase, middle tier application servers can be
added. Database instances can also be added to the existing RAC
cluster to meet the additional workload.
With the growth of
internet-based business operations, the web is the primary place of
user interaction. Most applications are coded in java or other
languages and are usually deployed through middleware application,
or java servers such as WebLogic, WebSphere, or Oracle Applications
Server. Java is also used in many of the stand-alone applications.
In this section, the issues surrounding JDBC connectivity to a
typical Oracle RAC database are examined.