Pre-migration details

note

Migration of existing projects to Camunda 8 is optional. Camunda 7 still has ongoing support.

This guide describes how to migrate process solutions developed for Camunda 7 to run them on Camunda 8, including:

• Differences in application architecture
• How process models and code can generally be migrated, whereas runtime and history data cannot
• How migration can be very simple for some models, but also marked limitations, where migration might get very complicated
• You need to adjust code that uses the workflow engine API
• How you might be able to reuse glue code
• Community extensions that can help with migration
• The Clean Delegate approach, which helps you write Camunda 7 solutions that are easier to migrate

We are watching all customer migration projects closely and will update this guide in the future.

What to expect

Before diving into concrete steps on migrating your models and code, let's cover some conceptual topics and migration readiness steps. The list below provides an outline of the sections in this guide:

• Conceptual differences
• Migration readiness
• Adjusting BPMN models
• Adjusting DMN models
• Adjusting source code

Open issues

As described earlier in this guide, migration is an ongoing topic and this guide is far from complete. Open issues include the following:

• Describe implications on testing
• Discuss adapters for Java or REST client
• Discuss more concepts around BPMN: Field injection that is using camunda:field available on many BPMN elements. Multiple instance markers available on most BPMN elements. camunda:inputOutput available on most BPMN elements. camunda:errorEventDefinition available on several BPMN elements.
• Discuss workload migrations (operations)
• Eventual consistency

Reach out to us to discuss your specific migration use case.