Simplified App Migration reduces the effort required for vendors to build reliable, high-performance migrations. Instead of deploying migration code within Data Center, vendors receive their application's data in a standard format, ready to download and process in their cloud environment.

Atlassian packages the following data specific to each application:

AO tables
Attachments
Custom fields
Entity properties
Mapping information for use during the migration process

This gives vendors control and flexibility over how they consume data in their cloud application. Data is provided incrementally as it becomes available, though vendors may also choose to process it in bulk once all data is ready.

Simplified App Migration is flexible — vendors are not required to adopt the full system. Vendors with existing Data Center migration code can continue to use it while selectively adopting parts of this system, such as consuming Atlassian-packaged data exports or mapping information. This allows vendors to incrementally migrate to the simplified approach at their own pace.

Orchestration

The migration timeline includes three phases: pre-migration, the migration outage, and return to service (when the migrated site becomes available on cloud). The migration platform notifies the vendor when data and metadata are ready to consume. The vendor's application then notifies the migration platform of progress and completion. Vendors can reduce outage time by processing static data (such as attachments) earlier, during the pre-migration phase.

The following diagram shows the full timeline for vendor integration, including pre-migration and incremental data consumption:

Minimum Integration

A minimum integration may wait for the All Migration Data Ready event, process the application data, and notify the migration platform when the app is ready to return to service. Site outage time can still be reduced, as the data export from Data Center can occur during the pre-migration and core product migration phases.

The following diagram shows the minimum integration timing: