PDF export hangs in Confluence when external image URL destination is not accessible
Platform Notice: Data Center Only - This article only applies to Atlassian products on the data center platform.
When exporting a page to PDF, the export process may hang up to 16 minutes before completing the export.
Confluence 7.13.2, 7.13.5
Steps to Reproduce
- Create a page in Confluence
- Add image URL links to the page, and ensure the URLs are not reachable from Confluence
- From the ellipsis menu, choose "Export to PDF"
This occurs because of a stuck thread in the export process that hangs due to an inaccessible image link. If multiple exports are triggered at the same time, it can lead to significant performance degradation.
The following error will appear in the atlassian-confluence.log file:
ERROR [http-nio-8090-exec-1] [extra.flyingpdf.impl.ConfluenceExportUserAgent] log Can't get image resource for urihttps://<confluence_hostname>/download/attachments/123456789/image_title.png?&api=v2, error: Unknown image format
Remove the bad image link URLs and retry the PDF export