Pages with broken macros will experience slower load times when gadget feed is present on the system

Summary

Pages with broken macros will experience slower load times if Confluence has individual gadgets or gadget feed added from a system with network latency.

Environment

• Confluence 6.8 and 6.9
• Gadget feed or individual gadgets added to confluence from another system, such as Jira.

Steps to Reproduce

1. Create a blank Confluence page
2. Add a broken macro to the instance by one of two methods:
3. Via Source Editor
   • Install Confluence Source Editor
   • Edit existing page and add a non-existing macro to it via Source Editor:

     <p>
       <ac:macro ac:name="testmacro"/>
     </p>
     

   • Save page
4. Via third-party plug-in
   • Install a Third-Party plug-in, for example, view tracker
   • Add a view tracker macro to a page
   • Go to add-on manager and disable the plug-in
5. Macro will appear as "Unknown macro: macro name" on the page
6. Go to General Configuration > External Gadgets
7. Either add a large number of gadgets individually or add gadgets feed with a large number of gadgets in it
8. Go back and load the page with broken macro

Expected Results

Page loads quickly, considering there is no other content except for a broken gadget

Actual Results

Page takes a long time to load, the more gadgets exist in the feed and the slower the connection to them, the longer page will be loading.

Notes

• It appears that gadgets metadata is being pulled in the background by a macro browser on pages with broken macros.
• The issue is caused by a CONFSERVER-55620 bug
• On consecutive re-load, page load is significantly faster, but clearing Gadget Metadata Cache from General Configuration > Cache Management will result in page taking a long time to load again.
• On our test instance with 48 gadgets in gadgets feed, the page with a broken macro took about 40 seconds to load, when it took milliseconds without the feed.
• Loading times are proportional to the number of gadgets, so although connection might seem fast to individual gadgets, each new gadget will stack and increase loading times:
  • Baseline with no feed or individual gadgets on a page with broken macro and no other content
    
  • 10 gadgets added
    
  • 24 gadgets added
    
  • 48 gadgets added or feed with 48 was added
    

Workaround

• The issue is fixed with 6.10.0, 6.6.7, 6.8.5, 6.9.3
• Make sure no broken macros are present on a page
• Removing Gadget feed and only adding individual gadgets that are required should help reduce load times