Children Display Macro slow due to poor permission check performance

1 - Summary

We need to improve the performance of permission checks in Confluence. The Children Display Macro is heavily affected by this issue. Currently, admin users are not affected by this issue.

2 - Steps to reproduce:

1. Install a Confluence 5.10.
2. Create a space.
3. Create around 3000 pages with the following command, replacing the "< >" tags:

   for ((i=1;i<=3000;i++)) ; do  curl -v -u admin:admin -X POST -H 'Content-Type: application/json' -H 'Accept: application/json' -d'{"type":"page","ancestors":[{"type":"page","id":<pageId>}],"title":'$i',"space":{"key":"<space_key>"},"body":{"storage":{"value":"<p>This is a new page</p>","representation":"storage"}}}' "<confluence-url>/rest/api/content/?os_authType=basic";  done
   

4. In the same space, add the Children Display Macro. Use the default configuration for the macro.
5. As an admin user, reload the page. Takes around 2-3s to load.
6. Login as a non-admin user and browse the same page that contains the children display macro. Takes around 100s to load.

3 - Workaround

• It is best to avoid using the Children Display Macro in parent pages that have many child pages OR
• You can specify the Parent Page, Number of Children, and Depth of Descendants to be displayed for better performance. You can tune it for smaller numbers.
  • Forced limit for "descendants depth" parameter to avoid rendering macros with an unlimited amount of descendants layers.

    CATALINA_OPTS="-Dconfluence.child-macro.max-depth=4 ${CATALINA_OPTS}"
    

  • Limit the number of children shown by the macro

    CATALINA_OPTS="-Dconfluence.child-macro.page-limit=4 ${CATALINA_OPTS}"
    

4 - Side Notes

• https://jira.atlassian.com/browse/CONF-31525 The Include Excerpts option is unrelated.