WebSphere Application Server V7.0: Concepts ... - IBM Redbooks

With this list of requirements, you can start to create the first draft of your design.
Target developing the following designs:
► Application design
To create your application design, use your functional and non-functional
requirements to create guidelines for your application developers about how
your application is built.
► Implementation design
This design defines the target deployment infrastructure on which your
application is deployed.
The final version of this implementation design will contain details about the
hardware, processors, and software that is installed. However, you do not
begin with all these details. Initially, your implementation design simply lists
component requirements, such as a database, a set of application servers, a
set of Web servers, and whatever other components are defined in the
requirements phase.
With these two draft designs, you can begin the process of formulating counts of
servers, network requirements, and the other items related to the infrastructure.
We describe this in 4.3, “Sizing the infrastructure” on page 106. In some cases, it
might be appropriate to perform benchmark tests. There are many ways to
perform benchmarking tests, and in 4.4, “Benchmarking” on page 107, we
describe some of these methods.
The last step in every deployment is to tune your system and measure whether it
can handle the projected load that your non-functional requirements specified.
For more details about how to plan for load tests, see 4.5, “Performance tuning”
on page 108.
4.2 Design considerations
The following sections discuss some points to consider when designing a
WebSphere Application Server deployment. They will most likely impact your
design significantly. We will talk in more detail about:
► “Scalability” on page 96
► “Caching” on page 98
► “High availability” on page 99
► “Load-balancing and fail-over” on page 100
► “Disaster recovery” on page 101
► “Security” on page 102
► “Application deployment” on page 104
► “Servicability” on page 105
Chapter 4. Infrastructure 95