Canvas taking high CPU using Chrome

[KONGHEYI]

Hi I have been using Canvas for a while, but this issue appears lately. I am using Windows 10. When I open the canvas page using Chrome, click into ANY course and goto the "quiz" / "file" / "videos" section, the computer's CPU usage naturally goes to as high as 60% even if I do nothing and left it there as it is. May I know if anyone faces a similar issue, and how can I resolve this?

P.S.: I have tried to restart my computer, or restart the Chrome, or clear Chrome browser data. None of them help. 

[KristinL · Accepted solution]

Hi Community Friends! 

If you haven't already, please open a case with Support. The L1 agents will be able to take a look at your account and be able to better troubleshoot with you on a 1:1 basis. Additionally, these cases will be linked and will help determine whether or not there is a larger issue. In either situation, you'll receive updates along the way!

• How do I contact Canvas Support?
• How do I get help with Canvas as a student? 
• How do I get help with Canvas as an instructor?

[KONGHEYI · Accepted solution]

I asked my school's Canvas support team, and from them, I managed to have some communication with the L1 and L2 Canvas support team. Currently, they claim that it is the problem of Chat tool being enabled in the course causing the spike in CPU. They promised to have their engineers looking into it, but do not give an exact timeline to address it. Therefore, it may help a lot if more people encountering this issue could voice out and raise the alarm to Canvas support team.

The email address I communicate with the Canvas support team is support@instructure.com

Alternatively, you can contact your school's Canvas support team, which will help to create the ticket to contact Canvas support.

[calvin237642 · Accepted solution]

Disabling the Metamask extension solves the problem.

If anyone can open a ticket with Instructure, please include this with the devs:

I used the CPU profiler in chrome and found out that `Window.postMessage()` keeps being called in a loop. Metamask injects JS into all webpages and it seems that both Canvas and Metamask are using the same API to send messages in the window. Somewhere a `window.addEventListener("message", ...)` is also calling `Window.postMessage()` creating a loop. A quick fix would probably be just add a field to the message identifying the message as being from Canvas and discard the ones that are not from Canvas.

[epolomsk]

Its been ovet a week now and still no solution.

Turning off extensions does not fix the problem.

It also seems impossible to get in contact or get a reply from Canvas support.

[Azniv]

This is happening to me too!! I open my computer and canvas literally swallows my battery percentage because of the high CPU usage. I went from like 70% to 20% in 30 minutes and my computer died during an online test!

Let's get this fixed, Canvas!

[KONGHEYI · Accepted solution]

Recently, I heard from the Canvas support team again. This is their response:

(1) Thank you for the reply back to us. Our engineers deployed a fix for the behavior we were seeing with this yesterday. If you are still seeing this happen, can you provide a link to a current example of where we can see this still happening in Canvas to investigate further?
(2) There was a problem with our code which was making a specific call to be run in a loop which was causing the high CPU. The code has been modified to stop this now.

If you are still having this issues / find the issue resolved, feel free to respond here so that the Canvas support team could have the accurate information. Thanks!

[jonespm]

Thanks for following up!

I think this was the fix (Fix postMessage loop with unsupported subjects), so maybe the postMessage investigation here helped. 

I re-enabled the extension that was causing issues for me and seems to be fine now. 

[JohnMacCormick]

Hi, just wanted to alert you -- the link in your post is invalid.

[JohnMacCormick]

I am experiencing the same issue on multiple browsers. Very high CPU usage when accessing pages on my course. I use the free version with no institutional connection. There appears to be no way to submit a bug report in this case. Here is a link to the course that consumes CPU on Edge and Chrome: Data Structures and Problem Solving (instructure.com) 

[JanKes]

I have been experiencing this as well for the last few weeks. Up to the point that opening one tab of Canvas only causes the page to crash after a few minutes. Very annoying. Please fix this.