Too many parallel downloads

[jkufner]

⚠️ Before posting ⚠️

• This is a bug, not a question or an enhancement.
• I've searched for similar issues and didn't find a duplicate.
• I've written a clear and descriptive title for this issue, not just "Bug" or "Crash".
• I agree to follow Nextcloud's Code of Conduct.

Steps to reproduce

1. Have a folder with many large files on a server.
2. Try to sync the whole folder. Does not matter if I select the folder, or select all the files in it.
3. Nextcloud Android app tries to download everything at once. Like random four of the files make it through, the rest times out.

Expected behaviour

The Nextcloud client should download the files one by one, queuing the rest. No more than two or three files shall be downloaded at once.

Actual behaviour

The Nextcloud client starts all the downloads at once.

Android version

15

Device brand and model

Samsung Galaxy Tab S9 FE

Stock or custom OS?

Stock

Nextcloud android app version

3.34.0

Nextcloud server version

32.0.0

Using a reverse proxy?

Yes

Android logs

No response

Server error logs

Additional information

The connections simply time out because it hits the limit of parallel connections on the server.

[alperozturk96]

@jkufner

Hello

Could you try with this QA version: #15806 (comment) ?

[jkufner]

Could you try with this QA version: #15806 (comment) ?

@alperozturk96 This looks like a step in the right direction. When I select several large files and click "Download", I get a notification for each of them, but only eight of them actually start downloading. The remaining notifications do not show the file name, just the app name and nothing else. The folder view shows icon badges consistent with the notifications. When a file finishes, it seems that one of the empty notifications comes to life and another download starts. So, this seems to work as expected, even though the notifications need some love (the pending state not rendered correctly and there is no option to cancel a download, either active nor pending). The download certainly seems to be way more reliable.

A bit of unexpected behavior is, that the downloads start from the last file, and the first file in the folder got downloaded last. I would expect the downloads to happen in the same order as I see the folder content.

It would be nice to have a summary notification somehow showing overall progress of all operations.

However, when I click "Synchronize" at a single folder, I get a notification about that folder and it shows no progress. After a while, when a file finishes downloading, there is a proper status visible in the notification ("N of M, filename") for a few seconds, but then it disappears. Also, file badges are not visible inside of the synchronized folder during the download, only when a file is downloaded, and the folder view does not update when a file is downloaded (I get the correct badges when I refresh manually).

Then I noticed a likely bug: When I select a folder to synchronize, let the synchronization start and then go inside and download the first file, it seems to get downloaded twice - once as started with the folder sync, then as started individually. This may be related to the sync badges not visible (the app seems to not know that the file is already being downloaded).

And one more thing (maybe a bit out of scope of this): When a download fails, there is no retry. For example if I turn off wifi during a download, I get the error notification about the download, but when I reconnect the wifi, nothing happens - it is like I never clicked the download button. I would expect the file to go back into the pending state, like before the connection is established, and retry later. Even better would be to keep the partially downloaded file and continue (HTTP Range request) the download where it stopped.