Overview of migration, coexistence, and interoperability

The goal of migration is to reconstruct your earlier version of WebSphere Application Server in a nearly identical Version 6.1 environment. One goal of coexistence is 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; another goal is to create an environment that 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.

Introduction

WebSphere Application Server Version 6.1 can coexist with Version 5.x and Version 6.0.x. Depending on the previous version of WebSphere Application Server, there might be port conflicts that need to be resolved. See Coexistence support and Configuring ports for more information.

WebSphere Application Server Version 6.1 migration leverages the existing configuration and applications and changes them to be compatible with the WebSphere Application Server Version 6.1 environment. Existing application components and configuration settings are applied to the Version 6.1 environment during the migration process.

If you use an earlier version of WebSphere Application Server, the system administrator might have fine-tuned various application and server settings for your environment. It is important to have a strategy for migrating these settings with maximum efficiency and minimal loss.

You can perform incremental migration of your WebSphere Application Server Version 5.x or 6.0.x configuration by calling the migration tools multiple times, each time specifying a different set of instances or profiles.

Migration involves the following main steps:
  1. Testing your applications in a nonproduction WebSphere Application Server Version 6.1 environment, and making any changes to the applications that are necessary to ensure that they run in that environment.
  2. Migrating those applications and your configuration to Version 6.1.

    This step can be performed by using the migration tools shipped with the product.

The migration tools migrate applications and configuration information to the new version as described in Migrating product configurations. See Using the migration tools to migrate product configurations.

The migration from WebSphere Application Server Version 5.x or 6.0.x to Version 6.1 is fairly routine. Important reference articles for this migration include the following articles:

If you neither migrate nor coexist with an earlier version of WebSphere Application Server, you are choosing to ignore the previous installation and you can run only one version at a time because of conflicting default port assignments. It is possible for both versions to run at the same time without conflict if you use non-default ports in the earlier version. To set up coexistence with WebSphere Application Server Version 5.x or 6.0.x, ensure that unique ports are selected during profile creation for the Version 6.1 installation. To set up coexistence with an existing installation of Version 6.1, select the radio button that states "Install a new copy of the V61 Application Server product" during installation.

You can resolve conflicting port assignments by specifying port assignments for coexistence during profile creation, by wsadmin scripting or by using the Servers > Application Servers > server1 > Ports administrative console page to ensure that WebSphere Application Server Version 6.1 can run with an earlier version.

See Wsadmin tool.

Coexistence processing changes the following configuration files:
  • virtualhosts.xml
    • HTTP Transport Port
    • IBM HTTP Server Port
    • HTTPS Transport Port
    • HTTP Administrative Console Port
    • HTTPS Administrative Console Secure Port
  • serverindex.xml
    • Bootstrap Address
    • SOAP Connector Address
    • [This information applies to Version 6.0.x and previous servers only that are federated in a Version 6.1 cell.] SAS SSL ServerAuth Listener Address
    • CSIV2 SSL ServerAuth Listener Address
    • CSIV2 SSL MutualAuth Listener Address
    • WC adminhost
    • WC defaulthost
    • DCS Unicast Address
    • WC adminhost secure
    • WC default secure
    • SIB Endpoint Address
    • SIB Endpoint Secure Address
    • SIB MQ Endpoint Address
    • SIB MQ Endpoint Secure Address

See Port number settings in WebSphere Application Server versions for more information.

Consider these issues in a migration or coexistence scenario:
  • Conflicting context roots when attempting to share the same Web server.

    Follow the procedure in Migrating Web server configurations to learn how to configure a Web server for sharing between WebSphere Application Server versions.




Related tasks
Migrating product configurations
Migrating and coexisting
Concept topic Concept topic    

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Last updatedLast updated: Aug 30, 2013 6:03:36 PM CDT
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