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.

[viera30]

I have the same issue, I noticed it today. If I have 2-3 tabs from canvas open, one of them crashes.

[Tarpstone]

Same problem here. For the last few days, opening just a single Canvas tab uses a third of my CPU or more (screenshot attached).

[mr_Austin]

we not alone. I am using MacBook pro 2017 and when i open canvas the fans are running at high. Canvas needs an update to fix this.

[T_k]

I've got the same issue too, only recently started happening in the last 2-3 days. 

as soon as I open canvas CPU usage jumps from 2-3% to 25-30% for chrome. 

currently on windows 11 

[Jsgoldshteyn]

I have been having this issue as well. In fact, when I only opened 4 tabs with canvas on it on Chrome + Windows 11, my CPU usage spiked to between 60-80%. This is very problematic and needs to be fixed.

[Chris_Hofer]

Hello @KONGHEYI, @Jsgoldshteyn, @T_k, @Tarpstone, and @viera30 ...

While I don't necessarily have an answer for you, I have been following this interesting thread.  If you haven't done so yet, you might want to reach out to Canvas Support to report this.  I'm not sure if what you are all experiencing would be considered "expected behavior" by the CPU or not, but it would be something that you might want to at least report to their help desk staff so they can create a ticket for it, and then you can get updates if and when this would be resolved.  I would also be curious to know what Canvas Support says.  So, if you could post an update back in this thread, that would be helpful...thanks!

[ChristopherRobe]

This is happening on Firefox as well. When I profile the page I get this result in the attached image.

[jonespm]

Which page were you on where you were seeing these messages? I believe that this Window.PostMessage is only for LTI messages so from like Quizzes Next? 

I did notice there was a commit added to "sync quizzes next and speedgrader" 2 weeks ago. Issues that involve polling and refresh could be related to continuous CPU usage. 

Do you see any extra network traffic or console errors? 

[epolomsk]

same problem for me: 1 Canvas tab shoots it up by 40%

and makes it impossible to delete files or edit anything

[Eirik1]

I have the same problem on Macbook air M1. My CPU usage increases to about 80 percent when having one canvas tab open in chrome. Google led me to this forum post.

Guess for now I will have to close the canvas tab after use. 

[ZihangChen]

Same issue here. Canvas uses 30%+ CPU while in quiz mode. Firefox user.

[epolomsk]

 I tried sorting this out with my colleges Canvas support last night and this AM 
they cant figure it out
Their suggestions were:
1) clear cache and cookies(as we know that does nothing)
2) close tabs (does nothing)

3) different browser (does nothing)
4) restart computer (does nothing)
anyone know how we escalate this to Canvas National's attention?!

Cuz I am getting nowhere

[Chris_Hofer]

@epolomsk ...

You can contact Canvas Support by following these Guides:

• 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?

Please report back after you talk with Canvas Support technicians so we know how they were able to help get this resolved for you.

[epolomsk]

Already tried those routes it only gets you to local college support

[epolomsk]

p.s. already reported that the local college canvas support could not fix the issue

[Chris_Hofer]

@epolomsk ...

I'm not exactly sure how your school's Canvas Support is set up...but some schools first use their own on-campus support (which it sounds like this is their setup), and then they can forward some tickets on to Canvas Support at Instructure if need be.  You might want to ask if they can escalate your issue to Canvas Support at Instructure about the CPU issues you're seeing.  Just a suggestion for you to try...hope it helps!

[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?

[epolomsk]

Spoiler

Spoke many times with L1 support, they are unable to remedy the situation

nothing they suggested worked

[epolomsk]

why is this issue being marked as solved?

It most definitely is not solved

[KristinL]

Hi @epolomsk  -  I know that the issue is not "sovled" but contacting Support is the solution at the moment. I'm sorry that there isn't an answer quite yet. (Though, @wes_carp did share some short-term solutions.) The more cases that Support sees and troubleshoots, the sooner they'll be able to share a true solution. I'll update this thread if one becomes available.

[epolomsk]

alas, my courses are mostly astronomy,
Its very dependent on images.

I cant turn off images because they are an integral part of my course content

[YinanZhou]

It is so misleading to mark this as solved.

[wes_carp]

Hi there, I've also been having this issue, and it's definitly not due to faulty/insufficient hardware.  What I've found for a short-term solution is to go into whatever browser you're using and disable images for whatever url your canvas site is on.  Doing so, then reloading the canvas pages, will make your cpu go back to normal usage.  However, I have found that if you open a new tab or whatnot, you'll have to reload the canvas tabs again as the cpu will pick back up for no reason. 

Hope this helps!

I'm on chrome btw. 

[akulkarni334]

This is a significant issue and some website issue on canvas's part. I've been having this issue anytime I got to the "Files" section of my course since this past weekend. It takes up so much of my CPU that my laptop gets too hot and my battery drains like crazy so I have to close that tab. This needs to be addressed immediately.

[momo_badarni]

Same exact experience! It just suddenly uses a crazy amount of CPU and eventually crashed the canvas page. This only started recently and was not the case in the past. I added screenshots of both task manger in chrome and on my system. There is no reason 3 tabs should blast an i9 to 100%...

[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.

[jonespm]

Do you have any browser extensions enabled and/or have you tried in private/incognito window to see if it has the same problem?

I was seeing high CPU but set a few extensions from Site Access "All Sites" to just "On Click" after I didn't notice the same problems in a private window and that fixed it. I'm not 100% sure yet which extension it was. It seems like possibly LastPass and/or Wappalyzer in my case. I can't get this situation to reproduce on any browser without extensions. 

[KONGHEYI]

I tried for:

- going incognito window;

- close all extensions on Chrome, or reset Chrome and clear all existing extensions

- switch to Microsoft Edge

- switch to Firefox

None of these worked.

Are you a technician or an engineer? It would really be nice if you could help in raising the situation to Canvas Support team's alarm. Thanks so much!

[jonespm]

No, sorry, I don't work for Instructure. Just a software developer and support at a customer institution. Trying to get ahead of this issue if it starts coming up for us to be able to provide as much feedback as possible to Canvas support and also personally curious about the cause of this. 

I was trying to reproduce this so I could profile the page like @ChristopherRobe had but it hasn't caused a problem for me. I also haven't seen this reported locally this week, but have heard of other schools where this is happening.

Based on that users Firefox page Profile it looks like it something related to an LTI tool with the Window.postMessage being called so frequently, but not sure where.

Thanks for the information! Hope this gets resolved soon. 

[epolomsk]

I turned off all extensions, but that didnt fix the problem.

[epolomsk]

I tried disabling the Chat tool in my course.

Didnt fix the problem.

[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.

[wes_carp]

Fixed mine, thanks

[JohnOt]

This should be marked as the official solution.

[KONGHEYI]

Sorry but where could I disable the 'Metamask' extension? Because I have never heard or installed this Metamask extension at first place, and currently I have no active extensions on my Chrome or Microsoft edge, but the problem persists.

[epolomsk]

What is metamask?

I dont have an extension with that name.

[Tarpstone]

Thank you so much for this, worked for me. Unfortunately doesn't look like it's applicable to everyone so hopefully the Canvas devs can figure out this issue soon!

[viera30]

Worked for me.

[WILLHASLETT]

I also had this issue but with the chrome extension called Windowed - floating Youtube/every website. I just changed the extension permission to only access/change data on YouTube.com, and that fixed the issue with Canvas.