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WAS v8 migration planning
The goal of migration is to reconstruct the earlier version of WAS in a v8.0 environment. Coexistence allows you to create a mixed-version environment that is not in conflict and allows the nodes of all versions to start and run at the same time. Coexistence also facilitates rollback and allows one or the other version to run at one time. Interoperating is exchanging data between two coexisting product installations or between products on different systems.
The migration process...
- Assessment
- Plan work involved
- In a test environment, migrate configuration and code
- Functional and performance testing
- Roll out new release to other environments
This topic is about migration planning.
WAS v8.0 migration leverages the existing configuration and applications and changes them to be compatible with the WAS v8.0 environment. Existing application components and configuration settings are applied to the v8.0 environment during the migration process. We can perform incremental migration of the WAS v6.x or 7.x configuration by running the migration tools multiple times, each time specifying a different set of instances or profiles.
Another option for migration is to install WAS v8, recreate the configuration manually, and then install the applications.
Mixed cells
A mixed cell environment can exist in two ways:
- Perform incremental node migration of the existing system.
- Migrate the dmgr to v8.0.
The dmgr has to be at the level of the highest node version. If we have nodes of the previous version, then this migration of the dmgr creates a mixed cell at the highest version of WAS.
- Migrate one node at a time to this new highest version.
This cell cannot be at a higher version than the dmgr.
- Migrate the dmgr to v8.0 and then federate older version nodes to the new version dmgr.
This form of migration is supported for only v6.0.2, v6.1, v7.0, and v8.0 nodes.
- Migrate the dmgr to v8.0.
- Federate nodes from v6.0.2, v6.1, v7.0, and v8.0 to the new highest dmgr version.
This method of incremental migration leaves the system in a mixed cell environment with nodes administered by a v8.0 dmgr. Your migration planning should eventually include migrations of all nodes to the v8.0 level to ensure consistent administration of the nodes.
A WAS v8.0 WAS ND cell can contain mixed releases of v6.x or 7.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 the tools issue a warning message that the nodes cannot be managed by the v8.0 dmgr. We can then perform one of the following actions based on your needs. Upgrade all v6.0.0.x and v6.0.1.x nodes to at least v6.0.2. This action allows the nodes to be administered by a v8.0 dmgr.
Existing functions continue to work in a mixed cell environment. You should be able to perform reasonable operations, such as run existing applications, perform management operations, such as addNode, create mixed cluster, configure the system, call Mbeans, and deploy applications. New function support in a mixed cell environment can be decided on a case by case basis - based on function, priority and available resources. Migrate product configurations
Migrate and coexisting application servers