How inter issue links are migrated in Phased migrations

Summary

Both endpoints must exist for inter-issue links to be successfully migrated. However, if the endpoints are not migrated from the same source to the same destination, these links will not be transferred.

Solution

Overview

In our migration limitation documentation, it is highlighted that

• Issue links (including link types) are supported and will be migrated.

• Links to issues or entities that are not migrated are not supported and won't be migrated

In these statements the second statement takes precedence. If both endpoints of the issue link are not migrated, the issue link won't be migrated. We will cover a few situations below and the expected experience

• When endpoints of the issue link are across separate projects

• When endpoints of the issue link have a missing entity due to migration failure.

• When endpoints are not between the same source and destination

Endpoints across separate projects

When the issue link is between issues in multiple projects, then

• If the projects are migrated in a singular plan, the links will migrate too.

• But if the projects are migrated in separate phases, then the latter phase will migrate the links. This occurs because in the first phase, both endpoints won't exist. But when both endpoints are available in the subsequent migrations, the links will be created.

Endpoints with partial migrations

When the issue link is between issues where one of the endpoints didn't migrate, the links won't be migrated.

• If the incomplete endpoint was due to a failed project migration, then the re-attempt of the project migration will migrate the links.

• But if the incomplete endpoint was due to a partial migration where a few issues didn't migrate, and rather than re-attempting the project, it was decided to recreate the issues via CSV import, then the links won't be created automatically. From the original migration perspective, the endpoints were incomplete. The CSV import of the missing issues alone won't be able to create the issue links. In these situations, the links could be created viaAPI.

Endpoints with varying migration paths

When the issue link is between issues across projects. If projects are not migrated from the same source to the same destination, then the links won't be migrated. Some examples are mentioned below for clarity

• If a link exists between Project A and Project B on Source A, Project A migrates to Destination A, while Project B first migrates to intermediate Destination B before moving to Destination A. Although both projects are on Destination A, links won't be created as they come from different sources.

• Another example is where Project A and Project B link on Source A. After migrating Project A to Destination A, a sandbox is created, and then Project B is migrated there. Both projects exist in the sandbox, but from a migration perspective, they are not on the same destination, so links are not created.