Delay between Canvas Mobile and Canvas?

[rgibson1]

A student indicated that there is a delay between Canvas and Canvas Mobile (changes. additions, etc.), causing her to miss a quiz. New one for us. Has anyone heard of that?

[rseilham]

rgibson1‌,

In what context? A page, assignment, quiz? There can sometimes be a delay, but enough to miss a whole quiz is unlikely. Your Canvas admins can probably do some research to see if she was in the app around the time she claimed there was an issue. 

[rseilham]

Hi rgibson1‌, 

I'm just checking in again to see if you were able solve this issue. Let me know. Thanks. 

[rgibson1]

Hi Ryan.

I think the issue in this case was her notification prefs were set wrong. But, it did raise a question regarding the delta between adding something into the browser and how long it takes to update in mobile.

[rseilham]

Yeah, rgibson1‌, that is a good question. This was adjusted recently on pages to be updated more often, but I'm not sure of the official refresh time. It's something we'll need to ask Instructure.

[peytoncraighill · Accepted solution]

Almost everything the mobile apps pull from the Canvas API is in sync with Canvas web. There are a couple of exceptions where server caching causes a delay, like with discussion replies. If a person posts a discussion reply in Canvas web, that may only show up in the API a couple of minutes later when the cache refreshes. But almost everything is instantaneous (e.g., you change a due date in Canvas web, the next second a student loads that assignment in the app and sees the updated due date). I haven't heard about any caching issues affecting quizzes.

As far as push notifications go - they're sent as fast as possible, though if you happen to change an assignment at the same moment that a thousand other instructors change an assignment, the push notifications queue up and may take a few minutes to process. We have a combination of automated processes and humans to handle queue spikes, so the time between an update to Canvas web and the resulting push notifications should either be short or instantaneous.