The new IBM WebSphere Application Server (WAS) v6.0 software introduces the concept of Server Profiles. Profiles can be thought of as a specific server runtime environment operating within a separate instance of the JVM.
Each runtime environment has its own configuration files, logs, properties, and other attributes. Profiles can make each Java 2 Enterprise Edition (J2EE) application server runtime unique and separate from the server binaries and from other profiles. The separation of static binaries from configuration files provides a number of benefits for system administrators.
The WAS v6.0 profiles are similar to the wsinstance tool provided with WAS v5.x, but with some important differences. The wsinstance tool creates configuration files for separate JVM instances, but shares other information across instances of WAS v5.x. In contrast, profiles draw a sharp degree of separation, so much so that each profile is separately administered with its own configuration, logs, J2EE applications, and other attributes. The separation that profiles provide allows for a unique instance of WebSphere that has not been available in previous releases of WAS.
Easier Than Multiple Installs
More than one instance of the same IBM WAS product may be required on the same machine. This is often the case if the administrator desires to keep a degree of separation between applications and environments. This may be the case if you have a development group sharing the same WebSphere install instance. When using the WAS profiles, each profile runs as its own 1.4.2 JVM instance, thus providing a physical as well as a logical separation between instances of the product. This offers an advantage over multiple installs because it saves space. In addition, service updating is simpler since an administrator only needs to maintain a single set of product binaries. Profiles can also be created and deleted more easily than with whole product installs. With the separation of product binaries and profiles, it's possible for a system administrator to allow groups to have access to the profile information that defines their application server, while at the same time locking down the WAS runtime binaries.
Easier Application Updates
Another useful aspect of profiles is the staging of application updates. In this scenario, you have updated an application and wish to test it on the targeted WebSphere Application Server. The problem is that an older version of your application is already running and being used. You could uninstall the application and reinstall the new update, yet that would require you to take the application offline and then reinstall if your test fails. A solution would be to create a new profile and test it there. The test profile will be operating in its own instance of WAS and will be logically separated, thus giving you a level of security and separation should your tests fail. Of course, it only protects you while running in the context of WAS, and not if the two applications are sharing the same database or any other shared resource the two applications may access.
