Interoperate multiple application server versions
WebSphere Application Server v9.0 is interoperable with other versions of the product under certain conditions.
Read Overview of migration, coexistence, and interoperability and Migration considerations. For resources to help we plan and perform our migration, visit Knowledge Collection: Migration planning for WAS.
Interoperability applies to WebSphere administrative actions, administrative communication and to application client requests. WAS v9.0 is generally interoperable with WAS v7.0 or later . However, there are specific requirements to address for each version. In general, we 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 v9.0 while leaving others at the older release level. This means that, for a period of time, we might be administering servers that are at the current release and servers 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. See Create application servers for more information.
- Clone migrations do not support a mixed release cell environment. All target profiles must be at release 9.0.0.3 or later. Clone migrations on WAS for z/OS are supported on versions 9.0.0.3 and later.
For web application clients, interoperability is provided by employing the HTTP server plug-in at the highest version of all of the application servers in the cell. For example, a cell comprised of WAS v9.0 and v8.0 application servers would use a supported HTTP server with a v9.0 plug-in. See Technote Web server plug-in policy for WAS for more information.
Tasks
- Apply required interim fixes.
All fixes are available on the Support site for WAS products.
- Upgrade the SDK used to one supported by v9.0.
Read Recommended updates 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.
Create application servers Migration Toolkit on WASdev