Chapter 2. About the Migration Toolkit for Runtimes

What is the Migration Toolkit for Runtimes?

The Migration Toolkit for Runtimes (MTR) is an extensible and customizable rule-based tool that simplifies the migration and modernization of Java applications.

MTR examines application artifacts, including project source directories and application archives, and then produces an HTML report highlighting areas needing changes. MTR supports many migration paths including the following examples:

  • Upgrading to the latest release of Red Hat JBoss Enterprise Application Platform
  • Migrating from Oracle WebLogic or IBM WebSphere Application Server to Red Hat JBoss Enterprise Application Platform
  • Containerizing applications and making them cloud-ready
  • Migrating from Java Spring Boot to Quarkus
  • Updating from Oracle JDK to OpenJDK
  • Upgrading from OpenJDK 8 to OpenJDK 11
  • Upgrading from OpenJDK11 to OpenJDK 17
  • Migrating EAP Java applicatons to Azure
  • Migrating Spring Boot Java applications to Azure

For more information about use cases and migration paths, see the MTR for developers web page.

How does the Migration Toolkit for Runtimes simplify migration?

The Migration Toolkit for Runtimes looks for common resources and known trouble spots when migrating applications. It provides a high-level view of the technologies used by the application.

MTR generates a detailed report evaluating a migration or modernization path. This report can help you to estimate the effort required for large-scale projects and to reduce the work involved.

2.1. MTR Features

The Migration Toolkit for Runtimes (MTR) provides a number of capabilities to assist with planning and executing migration projects.

Planning and work estimation
MTR assists project managers by detailing the type of work and estimation of effort to complete the tasks. Level of effort is represented in MTR reports as story points. Actual estimates will be based on the skills required and the classification of migration work needed.
Identifying migration issues and providing solutions
MTR identifies migration issues and highlights specific points in the code where an issue occurs. MTR suggests code changes and provides additional resources to help engineers resolve the specific issue.
Detailed reporting
MTR produces numerous reports to give both high-level views of the migration effort and details of specific migration tasks. You can view migration issues across all applications, charts and summary information about issues in an application, a breakdown of issues by module in the application, reports of technologies used, and dependencies on other applications and services. You can also examine source files to see the line of code where an issue occurs. See the CLI Guide for more information on the available MTR reports.
Built-in rules and migration paths
MTR comes with a core set of rules to provide migration assistance for several common migration paths. These rules identify the use of proprietary functionality from other application servers or deprecated subsystems from previous versions of JBoss EAP. MTR also contains rules to identify common migration issues, such as hard-coded IP addresses and JNDI lookups.
Rule extensibility and customization
MTR provides the ability to create powerful and complex rules. You can expand upon the core set of rules provided by MTR and create rules to identify additional issues that are important for your migration project. You can also override core rules and create custom rule categories. See the Rules Development Guide for more information on customizing MTR rules.
Ability to analyze source code or application archives
MTR can evaluate application archives or source code, and can evaluate multiple applications together. It can identify archives that are shared across multiple applications, which can help with more accurate effort estimation.

2.2. About MTR rules

The Migration Toolkit for Runtimes (MTR) contains rule-based migration tools that analyze the APIs, technologies, and architectures used by the applications you plan to migrate. In fact, the MTR analysis process is implemented using MTR rules. MTR uses rules internally to extract files from archives, decompile files, scan and classify file types, analyze XML and other file content, analyze the application code, and build the reports.

MTR builds a data model based on the rule execution results and stores component data and relationships in a graph database, which can then be queried and updated as needed by the migration rules and for reporting purposes.

MTR rules use the following rule pattern: 

when(condition)
  perform(action)
otherwise(action)

MTR provides a comprehensive set of standard migration rules out-of-the-box. Because applications may contain custom libraries or components, MTR allows you to write your own rules to identify use of components or software that may not be covered by the existing ruleset.

If you plan to write your own custom rules, see the Rules Development Guide for detailed instructions.