Installation planning

Before we begin any WebSphere installation, we would ask the three questions below to help prepare and plan for an installation.

• What version of Websphere is required to support your applications?

  • Investigations are made to ensure that your application will run in the version of Websphere you intend to install. A key point is to understand what version of the Java WebSphere version support. You can go to the following URL to view a WebSphere version compatibility matrix: http://en.wikipedia.org/wiki/Websphere. You may have to speak to your application developers or application vendors to accurately asses JVM requirements.

• Are there any OS tweaks for the platform required for the chosen version of Websphere?

  • It is important to understand what version of OS you are going to use. First decide which platform you are going to install on and then research what the prerequisites are for that platform. Each platform may have certain Operating System (OS) changes or optimizations which are stipulated for correct installation of WAS.

• What version of OS and fix packs are required to support the chosen version of WebSphere?

  • Not only do you need to understand the base installation version, you may also want to understand what the latest fix packs are to ensure that your version of Websphere is fully up-to-date. You can go to the following URL to find the latest WebSphere fix pack version: http://www-01.ibm.com/support/docview.wss?rs=180&uid=swg27004980#ver70. We will cover more about maintenance and fix packs in Chapter 10.

As mentioned above, we have chosen to use Red Hat Enterprise Linux in this book, as it is the most commonly used IBM certified Linux distribution used for Websphere; however, it is recommended that you visit the following IBM URL and read up on the prerequisites for installing Websphere Application Server 7.0 on Linux platforms http://www-01.ibm.com/support/docview.wss?rs=180&uid=swg27012369.

Installation scenarios

Before beginning an installation, it is advised that you think about the type of WAS install you wish to perform. There are several installation scenarios and knowing which components are available might influence your chosen installation path. You may also wish to think about coexistence or interoperability with other WAS implementations or helper services. Helper services are other applications and/or technologies that may be required for your applications to run correctly on WebSphere and function as per their design. This means you may have to consider installation requirements in addition to those of WAS.

The WAS installation process allows for two main actions. The first being the base binaries which are the core executables and the second being a profile. The base binaries are the product mechanics made up of executables and shells scripts, and can be shared by one or many profiles. Profiles exist so data can be partitioned away from the underlying core. Simply put, a profile contains an Application Server. When an Application Server is running, the server process may read and write data to underlying configuration files and logs. So, by using profiles, transient data is kept away from the base product. This allows us to have more than one profile using the same base binaries and also allows us to remove profiles without affecting other profiles. Another reason for separating the base binaries is so that we can upgrade the product with maintenance and fix packs without having to reconfigure our Application Server profiles. A conceptual diagram is shown below.

Profile types

During the installation process, you can decide to install different profile types. There are two main profile types: application server profile or a management profile. Your installation scenarios will determine which combination of profile types you will be selecting during the installation wizard. Below is a table explaining the different profile types:

Profile Type	Description
Application server	WebSphere has the ability to have multiple application server definitions using the same underlying base binaries. Each profile defines the attributes and configurations for a given application server. Each standalone application server can optionally have its own administrative console application, which you use to manage the application server. We will cover how to install a profile later in the chapter.
Management profile	A Management profile defines an administrative agent which provides a single interface (administrative console) to administer multiple application servers. We will cover the administrative agent in Chapter 8.