Installation guide

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Figure 5. Basic Multi-Tier OracleAS Deployment Topology
An Enterprise Deployment Scenario
There are a couple of good reasons why it may be desirable to consider more complex
deployment models. The more advanced topologies require more than three servers and
potentially more than three tiers. One reason to utilize a multi-server, multi-tier model is
scalability. Oracle active-active clustering techniques can be used to increase
performance as you add servers. Another important reason to use a multi-server, multi-
tier model is to achieve high availability. Even if the three server topology is sufficient to
meet your performance requirements, it offers little protection in case of server or
component failure. Each server is a potential point of failure for your applications, since
there is no redundancy. Fortunately, Oracle clustering addresses this issue as well,
providing redundancy and failover capability in case of server failure.
The architecture illustrated in Figure 6 is an Enterprise class, multi-tier topology for
Oracle Application Server. This features a variety of techniques for providing scalability,
load balancing, and high availability. One technique is to distribute components across
multiple servers. The set of distributed applications is considered an OracleAS Farm.