Currently information about all pages of a space have to be retrieved for the pages of this space to be scheduled for migration.
This is feasible for spaces with up to maybe ~15000 pages. It works also for more, but gets slower over time.
Technical background: the page list for a space is requested in batches from Confluence. The higher the batch start index, the slower Confluence delivers the results. This is by design, at least for Confluence < 7.18 (which introduced a new API to be faster).
While there cannot be done much about Confluence getting slower, the migration should already start to not lose the time with waiting.
Currently information about all pages of a space have to be retrieved for the pages of this space to be scheduled for migration.
This is feasible for spaces with up to maybe ~15000 pages. It works also for more, but gets slower over time.
Technical background: the page list for a space is requested in batches from Confluence. The higher the batch start index, the slower Confluence delivers the results. This is by design, at least for Confluence < 7.18 (which introduced a new API to be faster).
While there cannot be done much about Confluence getting slower, the migration should already start to not lose the time with waiting.