WAS v8.0 > Migration and coexistence > Distributed operating systems
Interoperating multiple application server versions
WAS v8.0 is interoperable with other versions of the product under certain conditions.
Supported configurations:
This topic is about configuration migration, such as migrating dmgrs and federated nodes in a network deployment environment. The Application Migration Toolkit for WAS provides support for migrating applications from previous versions of WAS to the latest product version. For information about migrating applications, read more about the Application Migration Toolkit.
Read Overview of migration, coexistence, and interoperability and Premigration considerations. For resources to help you plan and perform your migration, visit Knowledge Collection: Migration planning for WAS.
WAS v8.0 is generally interoperable with WAS Version 6.x and 7.0. However, there are specific requirements to address for each version. In general, you should apply the latest fix level to support interoperability. If this is not possible, then the following interim fixes can be used to support the environment.
We can upgrade a portion of the nodes in a cell to WAS v8.0 while leaving others at the older release level. This means that, for a period of time, you might be administering servers that are at the current release and servers that are running the newer release in the same cell.
Restrictions on using mixed-release cells:
- A mixed-release environment where some members are at an older release level might have some restrictions. For details, read the "Creating application servers" article in the information center.
- A WAS ND cell can contain mixed releases of v6.x nodes, but there is no mixed-node management support for v6.0.0.x and v6.0.1.x.
The v8.0 migration tools still migrate these nodes during deployment-manager migration, but they issue a warning message that the nodes cannot be managed by the v8.0 dmgr. We can then do one of the following based on your needs:
- Upgrade all v6.0.0.x and v6.0.1.x nodes to at least Version 6.0.2. This will allow them to be administered by a v8.0 dmgr.
- Migrate these nodes to v8.0.
Procedure
- Apply required interim fixes.
All fixes are available on the Support site for WAS products.
- Upgrade the SDK used to one supported by v8.0.
Read Recommended fixes for WAS for more information.
What to do next
This information is dynamic and might be augmented by information in technical articles that are available on the IBM DeveloperWorks WebSphere site. Check the site for the latest information.