Migration to Mule 4
For your Mule 3 apps to take advantage of Mule 4, migrate them to Mule 4 through one of the following processes:
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A fully manual migration of connectors, modules, transports, expressions, and API gateways to their Mule 4 counterparts.
For guidance with a fully manual migration, see Prepare to Migrate and review Manual Migration Process.
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A partially automated migration with the Mule Migration Assistant (MMA), which is available as an open source project on GitHub.
For guidance using MMA to assist in a migration, see the user documentation (on GitHub). MuleSoft suggests that you try MMA to determine whether you prefer it to a fully manual migration. Note that you can run MMA on a sample application by following steps in the Migration Tutorial (on GitHub).
- Important
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Mule Migration Assistant (MMA) is subject to the terms and conditions described for Community connectors. Additionally, Mule Migration Assistant is distributed under the terms of the 3-Clause BSD License.
A benefit of using MMA is that it automates part of the migration of Mule 3 apps to Mule 4. Though the MMA does not migrate the app entirely, it provides significant help with the following tasks:
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Migrating the project structure.
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Automatically creating descriptor files, such as
pom.xml
ormule-artifact.json
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Automatically performing many adaptations of the app’s code.
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Providing guidance on how to manually migrate components and patterns that cannot be migrated automatically.
MMA helps with such tasks, but it does not deliver a fully functional app. Some additional steps are required. Those steps include testing and can also include:
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Manual migration of unsupported components.
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Manual migration of complex MEL expressions to DataWeave that cannot be automatically converted by MMA.
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Manual migration of complex DataWeave transformations that cannot be automatically converted by MMA.
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Prior migration of the DataMapper with the DataWeave Migration tool, before running the MMA.
It is also important to note that the MMA does not support incremental migrations.