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

8.10 Managing application configuration settings
Almost all non-trivial applications require at least some amount of configuration
to their environment in order to run optimally. Part of this configuration (such as
references to EJBs, data sources, and so on) is stored in the application
deployment descriptors and is modified by developers using tools such as
Rational Application Developer Assembly and Deploy V7.5 or Rational
Application Developer for WebSphere Software V7.5. Other settings, such as the
JVM maximum heap size and database connection pool size, are stored in the
WebSphere Application Server configuration repository and modified using the
WebSphere administrative tools. Finally, there are settings that are
application-internal, usually created by the developers and stored in Java
property files. These files are then modified, usually using a plain text editor, by
the system administrators after deploying the application.
8.10.1 Classifying configuration settings
Configuration data can often be categorized into three different categories.
► Application-specific
This category includes configuration options that are specific for an
application regardless of its deployment environment. Examples include how
many hits to display per page for a search result and the EJB transaction
timeout (for example, if the application has long-running transactions). This
category should move, unchanged, with the application between the different
environments.
► Application environment-specific
This category includes configuration options that are specific both to an
application and its deployment environment. Examples include log detail
levels, cache size, and JVM maximum heap size.
For example, in development, you might want to run the OrderApplication with
debug-level logging, but in production, you want to run it with only
warning-level logging. And during development, the OrderApplication might
work with a 256 MB heap, but in the busier production environment, it might
need a 1 GB heap size to perform well. These options should not move along
with the application between environments, but need to be tuned depending
on the environment.
Chapter 8. Application development and deployment 301