Migrating applications to Liberty

Move your applications to WebSphere® Application Server Liberty with ease by using the migration tools to plan your migration, analyze your applications, and update your source code. The migration tools can help identify any differences between your current environment and the technologies in your new Liberty environment, such as Java™ EE 7 or Java EE 8 and Java SE 8 or Java SE 11.

1. Evaluate, inventory, and analyze your applications by using the command-line Migration Toolkit for Application Binaries.
   The application binary scanner provides several reports to help assess what is required to migrate your applications:

   • The application migration report combines the content of the Application Evaluation Report (--evaluate), the Detailed Migration Analysis Report (--analyze), the Application Inventory Report (--inventory), the configuration file (--generateConfig).
   • At a minimum, the Liberty server.xml file includes the feature list needed in a Liberty server based on scanning each application binary. If you generate this configuration file using an application deployed to a WebSphere Application Server traditional environment, more application-specific resources are configured. Use this file to configure your Liberty server by modifying or adding additional content to the Liberty server.xml file, or use the include element to include additional server configuration.
   • The application evaluation report evaluates the Java EE technologies used in your application to find the best-fit application platform.
   • The inventory report identifies the EAR, WAR, and JAR contents of your applications. It summarizes the use of Java EE technologies with counts of servlets, JSP files, EJB beans, JPA entities, web services, and RESTful services. The inventory report also advises on issues found in the application that can cause class-loading problems and other issues.
   • The detailed migration analysis report helps you better understand the type and scope of changes that your applications might require. The report also includes detailed help to assist with the analysis of the potential migration issues.

   You can run Liberty in various environments, such as on-premises installations, Docker containers, or cloud environments, such as IBM Cloud Pak for Applications. IBM Cloud Transformation Advisor helps you scan your entire WebSphere Application Server cell to analyze your applications to move to OpenShift. The advisor provides the migration reports available from the binary scanner and provides migration artifacts for moving to IBM Cloud Pak for Applications.
2. After evaluating your applications with Transformation Advisor or the binary scanner, update your application source code with help from the WebSphere Application Server Migration Toolkit.
   The Eclipse-based migration toolkit has the same rules and help as the binary scanner in the Eclipse IDE where you work with your code. It scans your source code to assist your migration in the following ways:

   • Identifies deprecations, removals, and behavior changes that affect the application
   • Provides quick fixes to automatically make updates when possible
   • Provides detailed help for each migration issue