要約

When a Confluence space is migrated using the following method, issues with attachment loading may arise:

• Take a backup of Confluence Cloud

• Restore it to an intermediate DC instance

• Then use Confluence Cloud Migration Assistant to migrate to the destination cloud

This article provides guidance on resolving the attachment loading issue.

概要

Migrating a space from Confluence Cloud using the above-mentioned steps may result in duplicate media IDs. This could lead to attachments on the destination site referencing incorrect Media IDs and failing to load.

This problem arises when data is copied from the cloud to the DC. This happens because the source cloud already contains media store IDs for attachments, which are then imported into the intermediate DC instance.

In the second phase of migration, as data is transferred from the server to the cloud, both existing entries and new entries are created for each attachment. A new mediaId is generated during upload, leading to two entries for every attachment in the cloud.

If the migration is not performed according to the specified steps, Confluence tables will be appropriately linked, and the media store will show attachments on the cloud. However, when retrieving attachments from the destination site page, it's noticed that different media IDs are assigned to these attachments. Consequently, these files' IDs don't exist in the media storage, resulting in a failed state where attachments fail to load on the cloud.

Workaround to remove duplicate MediaID

Follow the steps below to eliminate duplicate MediaID and prevent this issue from recurring:

1. Delete all the problematic space/data from the cloud. If you are looking to reset the whole Confluence site then follow the steps outlined in the documentation Reset and delete all data from your cloud site

2. On the intermediate DC, execute the following SQL queries. 

   DELETE FROM MIG_ATTACHMENT WHERE CLOUDID='<DESTINATION CLOUD ID>'; 
   DELETE FROM CONTENTPROPERTIES WHERE PROPERTYNAME = 'FILESTORE_ID';

3. Re-migrate the spaces.

Ticket tracking the long-term fix: CONFCLOUD-75835 - Doing a backup of Cloud attaches file store IDs