Performance Issue in Studio with Large Courses – Multiple Clipboard API Calls Causing Browser Crash

Development Architecture
, ,
1

Hello Everyone,

We recently installed Open edX Sumac.1 using tutor v19.0.0 in production. Now our client have started adding course content. However, we encountered a critical performance issue when managing large courses in Studio’s Course Outline Page due to multiple unnecessary AJAX requests.

Issue Description

Our client has added 150+ subsections in a single course. As you know, Open edX Studio now uses Micro Frontend (MFE) with React, which dynamically loads course content.

We observed that when we load the Course Outline Page, an AJAX request is triggered for each subsection to fetch the clipboard data:

https://mylmsdomain.com/api/content-staging/v1/clipboard/

For example, if a course has 10 subsections, this API is called 10 times, even though the response is the same. In our client’s case, with 150+ subsections, the browser crashes due to the excessive number of requests.

Screenshot-from-2025-02-25-13-33-20-02-25-2025_02_48_PM
Screenshot-from-2025-02-25-13-33-20-02-25-2025_02_48_PM1748×933 144 KB

What We Tried

  1. Disabling Copy-Paste Feature:: We attempted to disable unit copy-paste using the Waffle flag:
contentstore.enable_copy_paste_units

However, this flag had no impact on preventing these clipboard API calls.
2. Potential Optimization - Single API Call:

  • Since the clipboard API response remains the same across all calls, is there a way to fetch it only once instead of per subsection?
  • Has anyone faced a similar issue, and is there a way to cache or prevent redundant requests?

Questions for the Community

  1. How can we optimize or modify the MFE behavior to ensure the clipboard API is called only once per page load?
  2. Is there a reliable way to completely disable unit copy-pasting in Open edX Studio to prevent unnecessary clipboard API calls?

Any insights, workarounds, or fixes would be greatly appreciated. Thanks in advance for your help!

1 Like
2

This is being tracked here:

There’s a team that’s working through a number of bug fixes related to Studio authoring right now. I believe that this is on the list, but I’m not sure where it falls in relation to the other bugs. @braden might know?

1 Like
3

Our team is scheduled to implement a fix this week. Subscribe to the GitHub issue to be notified when a fix is available.

In the meantime you can try temporarily turning off the contentstore.new_studio_mfe.use_new_course_outline_page waffle flag to work around the issue.

2 Likes
4

Great to hear from you, @braden. I also want to work on this and aim to fix the issue this week. If there’s anything I can do to help, please let me know. I’m ready to give my best effort.

We have 150+ subsections, and it’s not able to continue because of this issue.