Mobile data consumption

[yasarciv]

The mobile application consumes a lot of data. Every time I write a message, it consumes 30-40 mb from my internet package.

[zingmars]

Some caching would really improve the app. Right now you have this and #3242 because the app doesn't appear to cache anything and constantly reloads all of the messages.

[yasarciv]

Maybe I had this problem but I didn't notice it last month or earlier 🤔 That's the situation last week.

[timabbott]

I don't think even if we reloaded all the messages, I'd expect the app to download 30-40MB from the server, unless you have some very large images.

So I don't think is a caching issue. It may be a thumbnailing issue, or something more subtle involving your usage pattern.

[yasarciv]

It's not normal for it to spend around 600 mb in five days.

[gnprice]

I agree that those numbers are quite bad!

It's likely that #3026 is part of the cause of this.

[gnprice]

@jcam, I'm curious to hear more about what you wrote at https://github.com/zulip/zulip-mobile/issues/3790#issuecomment-579937583:

this [the lack of thumbnails] combined with the reload-all-messages-every-time bug caused high enough cell data usage for the whole project to currently be a non-starter

What did reload-all-messages-every-time look like for you -- what's "every time", and what does it look like when the messages reload? I'm also curious how you determined what aspect of the app was causing high cell data usage.

I ask because there are several quite different issues in the app that could be described as "reload all messages every time", and it's not easy to know which ones have a bigger effect in practice. So knowing which ones you're seeing would help us tell which to prioritize.

[jcam]

It wasn't a behavior I particularly noticed, as I was on wifi most of the time. when i did switch to mobile, i noticed that with nobody else on the chat, and just one small image loaded, me sending myself a message or two quickly ate up multiple megabytes of internet bandwidth. From other members of the team: "there is apparently zero caching or thumbnailing for images in the message view; the full image files are re-downloaded from the internet every time a message view is refreshed, including when sending and receiving messages." "how is this going to work on poor/spotty and metered cellular connections? It just downloaded a 7MB cat.png six times because I wrote 'test' five times in a stream, using 60MB of cellular bandwidth. That does not bode well for things like "I'm on the hill during placement and trying to send photos" beyond those, we had two other comments: "tapping on a notification brings you to a random place in the stream" (which also happens just from switching between streams or to another app and back) "every time i type a response it ends up responding to the wrong topic" Combined together, we find the mobile app to be essentially unusable... I hope to see improvement, I really do like the desktop experience, and hope to use it in the future!

[gnprice]

Thanks @jcam for those detailed reports! Those specifics are very helpful.

The two that are about data consumption are caused by #3853, and greatly amplified by #3851. We have #3851 on our near-term roadmap, and that will make this a lot better.

"tapping on a notification brings you to a random place in the stream" (which also happens just from switching between streams or to another app and back)

Yeah. :-/ This is #3457.

"every time i type a response it ends up responding to the wrong topic"

Thanks for passing on this feedback. I've filed #3945 for it.

[jonas-schievink]

This is a serious problem for me, please consider improving this.