Re-opened from https://jira.atlassian.com/browse/JRACLOUD-76556

Issue Summary

Associating an Issue Type Scheme to a project causes a proxy timeout error.

Steps to Reproduce

1. A Jira project will need to have a large number of issues, (at least 1000).
2. Attempt to associate the project with another Issue Type Scheme.

Expected Results

• Association is successful.

Actual Results

• Association is unsuccessful; Jira stops - proxy timeout.

If you manually run a bulk move (e.g. from the result of JQL), the number of issues you can move in one operation is limited to 999 because of this memory limitation. If you do something that indirectly triggers a bulk migration (like changing the issue type scheme), this 999 limit is not checked (because you cannot partially migrate to a new issue type scheme) and so the migration may fail.

Workaround

• Backup your Jira data and save it in a safe place.
• Create a new project with a similar configuration to the current one, but already having the required issue type scheme.
• Move issues from the old project to the new one in batches of 999.

If it is OK to have all the issues in the new project, then you are done. If the project must be kept the same, then:

• Change the old project issue type scheme as required. This should succeed, because now the project is empty.
• Move issues from the new project back to the old one in batches of 999.