Trello consumes high CPU in Safari

[Ilia S.]

Hi,

I'm a web developer and using Trello for everyday tasks, thank you for such a great product.

2 days ago Trello started to consume lots of CPU in my favorite browser, Safari 13.1.2. There's no such issue in Chrome.

No other tabs are open. No intensive usage of cards. Does not matter which board is currently open. And I have Macbook Pro 2019 with 2.4 GHz 8-Core Intel Core i9.

I'm also having troubles with uploading images in cards. Maybe these issues are related.

[Michael Pryor]

Have you tried to see if you can reproduce in Safari Private mode?

[dominik.stypula]

@Michael Pryor 

Hi, I'm a web developer.
In the Chrome's Task Manager - Trello Board tab uses > 85% of the CPU.

I disabled ALL my extensions before the test. I'm just logged in to my Google Account.

Agree on that if you switch to Incognito Mode the problem does not exist.
But does that mean we have to use Incognito Mode to use the Trello?

I didn't see that problem in the other javascript-rich applications like Gmail, Google Sheets etc.

FYI: Problem doesn't exist if task is opened in modal, only if the trello board is opened, and tab is active.

[Michael Pryor]

You can try to delete your cookies and cache but the only difference between incognito mode and regular is 

- no prior cookies or cache

- no extensions enabled

If you continue to get odd behavior after resetting cookies and cache and you have all extensions disabled then my guess would be there is still an extension enabled. 

[dominik.stypula]

@Michael Pryor 

This is certainly NOT an extension problem. 

Only thing that I did was to remove ALL COOKIES from Trello domain and the problem is gone.

I've enabled all the extensions again, and none is causing the problem.

I assume that it's something with Trello cookies, or the localStorage. 
For now I cannot reproduce the issue.

If I stumble on it again I'll let you know.

[Michael Pryor]

Ok thanks.

[dominik.stypula]

Hi, @Michael Pryor unfortunately problem comes back again, after like 2 days of using trello.

Again only when Trello Board tab is active in browser my laptop fan is getting noisy and Trello starts to use around 70% of the CPU all the time when I just sit on the page doing nothing.

If you wish I can send you (or whomever is responsible for the JavaScript code in your team) profiling information from Chrome Tools which I've recorded.

It shows that there's problem with your scripts, however I cannot debug compiled JavaScript code for you.

[dominik.stypula]

I'm guessing function call on the screen
is causing some loop to happen because once i close the card modal, it triggers this and causes increased CPU usage. 

[Michael Pryor]

Can you go to trello.com/contact and hit contact support at the bottom and reference this thread, but also check the box that says "Give Trello support staff temporary access to your account." and include the url to the board you are repro-ing on with repro steps?

That way we can use your board to repro and figure out what is going on.