Overview

Migration consists of stages that include scoping, skills migration, code migration, and runtime migration. Refer to these articles for reference on these stages and other general information on the migration process:

• Part 1: Designing Software for Change
• Part 2: Stages of Migration
• Part 3: Migration assessment

• Migrate to WebSphere V5: An End-to-End Migration Guide

Note: These articles are not iSeries specific and may contain information not pertinent to iSeries.

WebSphere Application Server migration leverages the existing environment and applications and changes them to be compatible with the Version 5 environment. Existing application components and configuration settings are applied to the Version 5 environment during the migration process.

Migration involves modifying your applications so that they run in Version 5 and then migrating those applications and your environment to Version 5. The latter step can be performed by using the migration tools shipped with the product.

Migrate from Version 3.5.x to Version 5 involves migrating to the Java 2 Platform, Enterprise Edition (J2EE) 1.3 specification. Version 3.5.x applications are not J2EE compliant; hence, this process involves modifying the application.

Migrate from Version 4.x to Version 5 involves minimal change because both releases implement the Java 2 Platform, Enterprise Edition (J2EE) specification. Version 4 implements J2EE 1.2, while version 5 implements J2EE 1.3. Most Version 4.x applications run without change in Version 5.

Migrate from Version 5 Express to Version 5 (Base) or Network Deployment involves minimal changes because both releases implement a common set of the Java 2 Platform, Enterprise Edition (J2EE) specification.

Migration Tools

Product migration functions are provided by the the WebSphere Application Server migration tools. These tools perform migration from Version 3.5.x, 4.x and 5.0.x Express to Version 5 (Base) and Network Deployment. Migration configuration mapping describes how objects and attributes are mapped to the Version 5 environment by the migration tools. The migration tools are comprised of the following commands:

• WASPreUpgrade saves Version 3.5, 4.0.x, and 5.0.x Express configuration data and applications from a previous version to a backup directory. For more information, see The WASPreUpgrade script in the Administration topic.
• WASPostUpgrade restores Version 3.5, 4.0.x, and 5.0.x Express configuration data and applications into Version 5. This command uses the output from the WASPreUpgrade command. For more information, see The WASPostUpgrade script in the Administration topic.

The following tools are also available to assist you in migrating your applications:

• clientUpgrade migrates application client modules and their resources in an enterprise archive (EAR) file so that these application clients can run in WebSphere Application Server Version 5. For more information, see The clientUpgrade scripts in the Administration topic.

• earconvert migrates J2EE 1.2 application modules and their respective resource references to J2EE 1.3 application modules in an enterprise archive (EAR) file so that these application clients can run in WebSphere Application Server Version 5. For more information, see The earconvert script in the Administration topic.

• MigrateWC converts JSP Specification .91 or 1.0 application components to JSP Specification 1.1 components. It also converts Servlet 2.1 specification components to Servlet 2.2 specification components. The converted components are written to a new file. This tool is not shipped with WebSphere Application Server. For more information and to download this tool, see the WebSphere Developer Domain . Search in the Downloads section for MigrateWC.

• CACT analyzes compiled servlet and enterprise bean Java class files and provides information on any API that is deprecated or not supported in WebSphere Application Server Version 4 or Version 5. This tool is not shipped with WebSphere Application Server. For more information and to download this tool, see the WebSphere Developer Domain . Search in the WSDD Library section for CACT.

• WebSphere Development Studio Client (WDSC) is part of the WebSphere Studio family of application development tools. This tool can be used to import your application source files, set the desired J2EE version in the product, for example to J2EE Version 1.3, and rebuild the source files. Use of changed, not supported, and deprecated APIs are reported through compilation errors. After it is built, the application can be tested with the version of WebSphere Application Server that is included with the tool. This tool is not shipped with WebSphere Application Server. For more information on this tool, see the WebSphere Development Studio Client for iSeries Web site .