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

Automated migration with mixed version use
This migration approach also relies on the runtime migration tools provided by
WebSphere Application Server Network Deployment. Like when using the
“Automated migration with whole node upgrade” on page 485 in the first step the
existing WebSphere V5 / V6 configuration is recreated exactly in WebSphere
Applications Server V7.0. After that, additional new WebSphere Application
Server V7.0 nodes are added and applications can be migrated one by one when
they are ready. As soon as all applications of an old node are migrated, the old
node can be removed from the configuration.
This approach provides the following advantages and disadvantages:
► Advantages
– There is no need for a self-written comprehensive set of scripts. All
migration is performed using WebSphere Application Server tools.
– All the information in the current configuration is moved to WebSphere
Application Server V7.0. Therefore, you do not have to worry about
missing something.
– Allows more flexibility for application migration as migrations can be
migrated when they are ready.
► Disadvantages
– All the information of the current configuration is moved to WebSphere
Application Server V7.0. The disadvantage of this approach is that you will
also move configuration items that you no longer need.
– Care must be taken if you want to re-factor your topology during the
migration phase.
– Manual enablement of some upgraded features is still required.
15.2 Application development migration considerations
This section provides a general overview of what needs to be considered when
migrating applications between WebSphere Application Server versions.
486 WebSphere Application Server V7.0: Concepts, Planning, and Design