Reading Time: 7 minutes

In May 2020, we announced the general availability of Mule 4.3, Studio 7.5, and MUnit 2.5. This release concluded a long internal journey with several objectives: hardening and stability, performance parity between Mule 3 and Mule 4, and closing developer productivity gaps (API specification lifecycle in Studio) in Studio 7. As we made this release public, we achieved an important milestone in Mule 4’s evolution. Mule 4.3 is now better-equipped than ever before to welcome Mule 3 applications into Mule 4.

Mule 4 was re-architectured, in part, to offer a more declarative integration definition language, and with it, simplifying the creation of integration applications. You can read some of the Mule 4 highlights in greater detail with the blog 10 ways Mule 4 will make your life easier. Mule 4 also introduces other important capabilities such as a simplified and improved threading model, and classloading isolation which offer a platform for better isolation and application stability.

latest report
Learn why we are the Leaders in API management and iPaaS

The question remains: If I have applications on Mule 3, how can I move to Mule 4 and take advantage of all the innovation Mule 4 has to offer? 

There are many different ways to move Mule 3 workloads to Mule 4. MuleSoft is excited to announce the public release of an open-source project, the Mule Migration Assistant (MMA) to help businesses easily migrate Mule 3 applications to Mule 4. You can find everything MMA-related on the MuleSoft public GitHub repository

Introducing the Mule Migration Assistant

The Mule Migration Assistant is a command-line assistant that assists in the migration process by converting select components of a Mule 3 app to a Mule 4 app. This assistant will not complete 100% migration — adjustment will be required and a migration report is provided after the assistant is run. The Mule Migration Assistant does the heavy lifting of crawling Mule 3 application logic and structure and methodically converting the project structure and common connectors or processors into Mule 4 compatible components.

When the assistant finds something it cannot migrate, it will be marked as an error and point the developer to documentation on how to move forward. Customers can clearly see what the assistant does and does not migrate. More details on the MMA can be found on the GitHub self-contained documentation.

While the Mule Migration Assistant can offer a great start to complete the migration of a particular application in Mule 4, it is equally important to leverage the MMA-generated report as a way to understand what manual post-MMA execution actions are needed. Depending on the flagged actions, teams can determine the level of effort required in completing the migration. As developers run the Mule Migration Assistant across multiple Mule 3 applications, it is possible they will find common issues that need to be resolved. In this way, the Mule Migration Assistant can be leveraged to get insight and information on the level of effort before attempting to migrate a Mule 3 application to Mule 4.

We strongly encourage our customers and partners to take a look at this powerful resource. It provides a great alternative to re-writing Mule 3 applications from scratch. As the Mule Migration Assistant is also open source, anyone would be able to make tweaks to specific situations and even use the existing extensibility framework to add new converters that would apply to all Mule 3 applications migrated using MMA. MuleSoft welcomes its community to embrace, evolve and enhance this baseline framework to smooth the migration of Mule 3 applications to Mule 4.

How to get started

At MuleSoft, we are very excited to open and share the Mule Migration Assistant with our extended community and we hope to drive more value together with this Open Source project. Please check it out at the MuleSoft public Github repository.

For further details, please see the video below: